I am considering a 24x32 home with an 8x12 porch along one 24' side giving me a 8x12 porch and 8x12 dining room.
What I am concerned with at this point is the placement of piers for the foundation. I thought maybe a 8x8 grid which would give me 20 piers total (4 for the 24' width x 5 rows for the 32' length) and using 6x6 posts as my foundation rim?? to which I would use 2x10 (again not sure here) for my floor joists on top of the 6x6 post and 2X10 encompassing the floor joists.
I have been studying ScottA's pictures and think it would be easier to use block for my piers instead of 6x6 PT piers (last MUCH longer too).
Will this work? Is is overkill? Need help please.
Scott Gleaton - Alabama
For something like a 24 foot wide all you really need is a beam down each long side and one down the center. Concrete block piers would be excellent. The size of the beam and the bearing capacity of the soil determine what the spacing would be. I do not have figures on that, but an engineer or architect could calculate it.
The floor joists would be placed across the top of the beams. 2x8's on 16" centers could be used but are getting close to the maximum span; 2x10 on 16" centers would definitely give a solid stiff floor as well as more room for insulation.
If I understand the porch and dining room thing correctly you plan adding these to the 32 foot length, with the porch on one side of the 24 foot end and the dining room on the other. Correct? How do you envision the roof; an extension of the house roof covering the porch as well?
I agree with Don on only making 3 rows of piers. On an 8' spacing you'll need to use a triple 2x8 for your beams asuming a single story. The spacing on my piers is only 6 1/2'. With the blocks running with the beams this leaves 4'10" clear between the piers for the beams to span. your's would be different. Need to check the span tables for your floor joist size.
The way I self engineered my piers was to determine the weight of the house. To do this you'll need the square footage area of the floors walls and roof. I figured 40# per sq. foot for floor, 10# per sq. foot for walls and 40# per foot for roof. If you where in a higher snow load area you'd need to add the extra snow load. I figured mine fo a 30# snow load. Keep in mind that nearly all the wieght will be on the long outside beams and piers. The inner piers will carry half the floor and half the end walls plus any interior walls. My soil is suposed to carry 5500# per sq foot. Each 2x2' pier footing has a bearing area of 4 sq.ft so this is 22,000 pounds per pier. Your soil may not carry near this much weight. Your footings should sit on undisturbed soil below the frost line and be well drained.
(https://i370.photobucket.com/albums/oo150/sgleaton/lakview.jpg)
(https://i370.photobucket.com/albums/oo150/sgleaton/lkviewfp.jpg)
Here are images of both the floorplan and the completed project. I hope this helps you guys better than my messed up descriptions.
This is the way I calculated mine.
http://www.mcvicker.com/resguide/page013a.htm
According to this chart for a 12' span you could do a 4x8 girder with piers at less than 4' O/C or you can go with a 6x8 girder with piers at 6' O/C.
I tend to like charts like these because they help me calculate the cost of different options, such as the cost of changing the piers vs. beam size. More piers = smaller beams. You can calculate what is most cost effective for you.
I would check to see if your soil holds the normal load. The building local building inspector will usually tell you what he wants.
squirl doesn't that put me right back at 8x8 spacing on the piers? I am so confused.
I don't want to have to special order anything (more $$). 6x6 PT posts are readily available but 6x8 would have to be special ordered.
The chart that Squirl is using is concerned ONLY with the floor loads
• 40 psf live loads = people, furniture, parties, etc.
• 10 psf dead loads = framing materials, floor coverings, interior framing, etc.
Those charts do not cover the loads (dead or live) of the roof, loft or anything above the floor. The biggest of these in your design will be the snow, wind and roof structure itself.
When you design a foundation you have to do a load trace. You start at the top of the roof and work your way downward accumulating the areas and what their design loads are and distributing them to the structural members (walls and beams) that will carry them to ground. The beams carry that accumulated load (in PLF = pounds per lineal foot) and deposit them at the footings where they turn into PSF = pounds per square foot based on the carrying capacity of the soil (as Don has described).
In stock plans this is normally done by the designer/architect for standard snow loads and average soil conditions. What is in your plans?
Are you talking posts or girders? This chart is to explain how many posts/blocks/piers you need based on size and spacing. Of course this could change based on your local soil conditions. Many people build their girders from 2 by lumber nailed and glued.
http://www.mcvicker.com/resguide/page008.htm#FOOTINGS
How deep the footings have to be is regional.
So, If you put three rows of piers as many have suggested. One row of piers down each side of the house and one down the center you would have around 12' span for the floor joists. You would run a girder beam under the floor joists over top the posts coming off the piers. You would need to space the posts based upon the size that you use for the beams. Also depending upon the size that you use for the posts you would.
The general rule is to use pressure treated wood when it touches concrete. This is also the code in some areas. Some like using PT for any exposed wood because of the longevity. You can use untreated wood with treated wood. So what many people do is pour piers, use 4x4 or 6x6 PT posts, and use built up regular 2X lumber built up to 4x or 6x girders. When you eliminate the posts you are touching the concrete block directly to your girders. In this case you need to use PT wood girders or some type of protection. Concrete holds moisture. Moisture and wood do not mix. Many other people here would probably be better at explaining it than me, but I tried.
Sometimes a picture is worth a thousand words.
http://www.jshow.com/y2k/listings/7.html
John and Don are right. I just use this for a general calculation. The local building inspector will usually tell you what is standard for your area.
Considering the lengths required it may be easier to use the built up beam method, staggering the joints over posts. My beams are larger than required but provide a very solid platform. 4 layers of 2x10 DF#2 per beam.
Those tables are confusing and not very comprehensive, even for floor joists.
The beam/girder table are only for floor load and assume 40 psf - quite common but some areas are higher or lower. They are limited to Doug Fir - Larch and appear to favor some sawn beams rather than laminated beams of 2x stock which is what most people will use.
The joist tables are limited to Doug Fir - Larch and only show 1/360 deflection.
The tables linked from this site with a very good explanation by our host, John, are far better.
Explanation http://www.planhelp.com/public/98.cfm (http://www.planhelp.com/public/98.cfm)
Tables http://www.awc.org/calculators/span/reversecalc/reversecalc.asp?feet=13&inches=0&species=Douglas+Fir-Larch&member=Floor+Joist&deflectionlimit=L%2F360&spacing=16&liveload=40&snowload=-1&deadload=10&wet=No&incised=No&submit=Calculate+Span+Options (http://www.awc.org/calculators/span/reversecalc/reversecalc.asp?feet=13&inches=0&species=Douglas+Fir-Larch&member=Floor+Joist&deflectionlimit=L%2F360&spacing=16&liveload=40&snowload=-1&deadload=10&wet=No&incised=No&submit=Calculate+Span+Options)
You can choose different woods and loads 1/480 is useful if you are going to put tile over the subfloor for example
The above charts do the best job I know of designing rafters and joists. But when the joists and walls sit on beams (or girders) the sizing and spans of these get more complicated as I tried to explain in the load trace discussion.
For my designs I use a computer program to analyze the load trace and pick the size and grade of the members based on the span and accumulated beam loads.
The best discussion of this process, along with a method of engineering that involves only a calculator comes from one of the great owner builder teachers - Charles Wing. See the books "From the Ground Up" and "From the Walls In". He taught me everything I needed to know about engineering. Lots more than I learned from the overly complex engineering course in architecture school!
(Note: these books are hard to find and out of print.)
Now that I see the proposed plan things are a little clearer. When you stated a 24 x 32 building I automatically assumed the beams would run in the long direction. Assumptions nearly always lead to misunderstandings. d* The illustrated plan is actually a 24 x 24 building with a room bumped out under a shed roof. Then the porch is placed in the inside corner formed by that. That's how I see that. Others may differ.
When thinking about this also remember that the exterior porch floor should be 1 to 2 inches below the finished floor level inside.
Viewing that floor plan on the screen, I now visualize it as three parts; the 24 x 24 main cabin, the 8 x 12 room and the porch.
The main cabin beams would run sideways across the screen, in the same direction of the roof peak. There would be a central beam between them. The roof loads would then transfer down to the two 'outside' beams.
The dining room would be built as an addition. That would require an additional beam placed under the 'bottom' wall as drawn on the plan. (12 ft wall with twin windows).
Lastly the porch would be added using PT wood from the porch deck down.
The above is not as easy as building a square or rectangle and adding a porch on one side or end. At least it's not so easy without detailed plans. Not impossible; simply more difficult. At least that is how I see it. If anyone has a better method please add your thoughts.
Yes Don:
A agree with your analysis.
(https://i56.photobucket.com/albums/g166/jraabe/loadtrace.png)
In the above diagram the red lines are girders carrying the floor and wall loads. The green lines are where the roof loads will land (assuming a truss roof for the main building and stick framed at the porch and dining areas).
This can show us where the load bearing walls will be and where headers will be a concern.
I use these as a general guide because they are similar to the many designs I have seen built here.
Like this one. http://www.countryplans.com/lemay.html
These seem to be 6' O/C 4x4 posts and 4x8 beams with an 8 ft span for the floor joints. That is almost identical to the chart for #2 Douglas fir beams. If this could survive lake Michigan snow loads, I wasn't as worried. I always try and make sure I am scaled back by a few inches to be to be on the safe side.
The American wood council site is better for calculating the span options for different kinds of wood.
Note that the LeMay project and the post and pier foundations for most of my small structures use a gable roof and full span floor joists landing on the same girder. That simplifies greatly the design of the girders and pier spacing. Those layouts can be followed as a rough guideline only for similar designs.
The stock plan discussed above (not mine) is quite different and has more complex loading especially at the foundation and with some non-obvious load bearing walls.
Thanks everyone for trying to explain this to a wooden-headed ding-dong (ME).
I have the plans in hand for this cabin. However, it only shows for a slab foundation. I want a crawlspace. The floor joists are drawn as front to back with cross member center of the 24x24 running from the left to right. Would I place my footings at ZERO, TWELVE and TWENTY-FOUR feet in the 24x24 area, giving me a total of 9 piers there and adding 3 for the bump-out room and porch on the front, then building my porch similarly to that room? Is that what John and Don are so graciously trying to tell me. HIT ME IN THE HEAD IF NEED BE. I understand some of this stuff but not a contractor and have to make sure I get it right the first time.
Quotegiving me a total of 9 piers there
You
could do that but you would need a pretty stout beam to span that far.
You are going to have beams @ 0', 12' & 24'
Piers on 6' centers would allow a reasonable size beam. That would be 15 piers under the main 24 x 24 structure.
There are other solutions but that one makes the most sense to me.
so that I am understanding this:
15 piers (basic cement block with cement and rebar inside), 3 girders (6x6 PT posts)
on top of that I would use 2x10 or 2x12 for rim joists and floor joists. Maybe I am overthinking this but would you put double 2x's perpendicular to the girders in the "box" that you will be creating on the top of the girders and then put floor joists perpendicular to these doubled 2x's?
The girders/beams would not be 6x6 posts. They would most likely be built of several layer of 2x10 or 2x12. (back to the load trace)
The floor joists would run perpendicular to the beams. They can be hung between the beams but on top is better.
I had another thought. The wall between the living room and bedroom is not on the center line. Do the plans show trusses for the roof? It may well have been designed without interior load bearing walls, the roof load being supported by the front and back walls of the 24x24 box. If that is the case and you want to go with trusses the loads on those beams will be substantially higher than on the center beam that would then only support 1/2 the floor load.
If that is the case what do the plans show for a header between the kitchen & dining area? It would need to be pretty stout.
I'd like to take a step back before going forward.
Are any of the interior walls in your plans noted as being load bearing? If so, which ones?
What size is listed for the ceiling joists and what direction do they run. Both for the 24x24 and the 8x12 areas.
Quote from: MountainDon on January 28, 2009, 03:13:15 PM
I'd like to take a step back before going forward......
Killjoy! Full speed ahead... blindfold please.
Quote from: MountainDon on January 28, 2009, 03:13:15 PM
I'd like to take a step back before going forward.
Are any of the interior walls in your plans noted as being load bearing? If so, which ones?
What size is listed for the ceiling joists and what direction do they run. Both for the 24x24 and the 8x12 areas.
2x6 16" O.C. ceiling joists runing from front to back wall (both), 2X8 rafters 16" O.C. with 1x6 collar ties 32" O.C.
Floor joists are 2x10 16" O.C. running same direction as above. porch is 2X8 24" O.C.
As far as I can tell there are no load bearing walls ( I am guessing it would say LB or Load Bearing).
By the way, there is a built up beam of 3-2x10 between the kitchen and the front dining area. (5 1/2" wall) and the wall between the kitchen and bath is 5 1/2" also.
People I do apologize for not understanding this but the plan shows only a concrete foundation.
I'm confused.
QuoteHowever, it only shows for a slab foundation.
I thought you said it had a slab. Where are the floor joist coming from?
2x6 ceiling joists won't span 24'. Either those are the bottom chord of trusses or there is a bearing wall somewhere.
John C you are no more confused than I. I guess that the bedroom wall between the living space and bedroom must be a load bearing then??????
The plans do not show it as such.
Also, forgive me with the use of terminology as I am not up on it. The foundation shows a wall around the perimeter of the main building (excluding porch) with 3 piers center of the 24x24 and a beam, with another beam where the 8x12 room and kitchen meet.
I thought that you could use 6x6 for your beams and build the flooring platform on top of that. I am sure I have seen other projects with such on here.
So you have a crawlspace, not a slab.
What is that perimeter wall made of? Concrete blocks? How many high?
What's on top of the 3 piers...under the floor joists?
They are essentially on 6' centers ... correct?
There may have been a house that used 6x6 for beams but that would, in general, be an inefficient use of material. Usually beams are deeper than they are wide ... say 2 - 2x10's on edge, and they are sized for the specific loadings. 6x6's might be used as posts in lieu of the concrete piers shown on your plans
I don't know why but all of the sudden this is beginning to make some sense now. CLEAR AS MUD!
There are 3-2x10 with staggered joints on top of those blocks and a pocket for those on the foundation walls. The foundation is stated as 8" poured or CMU. The three piers are show 5'8" O.C. from the inside of the foundation wall.
So, in hopes I finally understand this, piers - 6' O.C., on top of this I would laminate 2x10 and set on end. and boxed in with 2x10 also then put my joists inbetween rim joists and beam. Do I need a mud seal (board laid flat on the perimeter)?
So somebody has done the engineering and come up with 3 -2x10's on edge for a center beam.
That does not mean the outside beams would be 3-2x10's on edge. Somebody needs to actually calculate the loads.
Joists could go between the beams but on top is usually better. Search the forum. It's been discussed before.
Before you go off on this path will the local building department let you do it? If they are going to make you do a perimeter footing anyway just build the crawlspace as shown on your plans.
There are no specific codes in my area. john C, you stated build on top of beams, thatt is why I thought using 6x6 PT would work for the beams and build my subfloor on top of that. Would that not work? I am afraid the expense of the proposed foundation would not work for my budget, that is why I am asking these questions.
- Block piers as per ScottA
- 6x6 beams bolted to these piers per spacing requirements stated (6' O.C.) for a total of 3 rows of 5 piers in 24x24 area plus 1 more on front side where bump out room starts and 3 on front of that room (Total - 19 piers) with beams encompassing the foundation area
- 2x8 or 2x10 rim joists and floor joists on top of the beams
- build porch just like a deck (according to plans)
Will this work or am I still WAY off?
I wouldn't use 6x6 lumber. Too much likelyhood of it warping with the crappy wood they sell these days. I'd go with a built up beam made of 2 by lumber in the longest lengths practical stagared spliced over the piers. It will likely cost less than 6x6 as well. My beams are made of 3 boards nailed together with 20 penny nails stagared top and bottom on a 16" spacing nailed from both sides. In other words if the top nail is on one side the matching bottom nail is on the opposite side.
The short answer is that you haven't provided enough information for anyone to determine if 6x6's would be strong enough. You may be way off, maybe not. I don't understand the affinity for 6x6's as beams.
The center beam on your plans is a nominal 6x10 (3-2x10's). That is stiffer than a 6x6 beam. The outside beams bear different loads. And the beam that bears the porch loads has a different loading than the one at the other end of the house. John_R has gone through what he calls a load trace. Somebody needs to do that.
What loads are carried by the center beam. Certainly 1/2 the floor load. It would seem there is a bearing wall and 1/2 the ceiling load is also carried by the center beam. Are any of the roof loads carried by that beam? What are the roof loads in your area?
In real terms the additional cost of the perimeter foundation is really small compared to the total cost. Have you looked into having an engineer spec the alternate foundation? Have you contacted the designer to see if an alternate foundation plan is available?
FYI: Built up beam info ...
http://www.countryplans.com/builtupbeam.html (http://www.countryplans.com/builtupbeam.html)
I hear what you're saying JohnC. If he uses 3 2x6's built up into a beam and spaces the piers 6' on center with the blocks running with the beams he should be fine so long as those beams are under the load path. If that center wall is bearing then it needs a beam under it. I'm assuming the ceiling is vaulted in the living area?
Just a note of something I've noticed. Alot of these stock cabin plans are designed for snow country so they can be overkill engineered for a southern build.
I need to point out that is is important to determine that the soil will support the piers.
I don't know Scott. As you go farther south in Alabama you get closer to hurricane country. There's no real snow load anywhere in Alabama, but the design wind loads get higher, towards 140 mph in the extreme southern part of the state. He described the plans as having ceiling joists so I'm guessing no vaulted ceiling.
Without getting any real numbers on loadings were in the dark.
I'd agree with the hurricane issue. If he's near the coast an engineer might be in order.
I'm not certain what I'd do about hurricanes other than use Simpson H1's for the rafters.
Do you think the joists would be okay toe nailed to the beams as in any place not faced with hurricanes?
Would the posts be PT 6x6 set directly in the ground a couple feet. If drained well that could work and not be too bad for hurricanes? Or would they be CMU's (concrete masonry units, for those who weren't sure. Would they be laid level and high enough so piers could be done away with? If so they could be tied to the CMU's with Simpson straps.
That thought raises the question of how high off the ground is desired? Code says that the bottom of the beams be no closer than 12" to the ground, IIRC.
That's just a bunch of random thoughts; thoughts that need answers in making this change from what the plan shows to what is wanted instead.
FWIW, IF I was not wanting to pay an engineer to come up with something certified for the foundation, I would guess that you would be quite safe with the two outside beams being built up 2x12's in four layers. I would lay the beams and joists out as shown in this very rough hand sketch. I'd sheath the floor with 3/4" T&G Advantech sub flooring, nothing less as this may be exposed to some wether before it gets dried in. Then I would build the rest of the cabin on that platform.
EVERYTHING above and below is guesswork. There are no engineered calculations to prove anything.
(https://i133.photobucket.com/albums/q75/djmillerbucket/construction/beamsjoists.jpg)
QuoteDo you think the joists would be okay toe nailed to the beams as in any place not faced with hurricanes?
No, that wouldn't do. In ye old days we used the metal plumbers strapping, nailed to the beam, nailed to and up & over the joist and nailed to the beam on the other side. you could let it into the top of the joist if you were feel'n fancy. Today there are lots of connector choices.
After hurricane Donna hit the Key a friend of mine was renovating a house in Islamorada that had basically been underwater during the storm and had survived the winds and storm surge full-on. It had seaweed lodged in the soffits.
The house had been built after the Keys took a terrible hit in 1935. The only remains of the CBS house next door was the slab, but the old wood house hadn't budged. Randy said they pulled off some siding and he stuck his hand inside the wall and ran it along the underside of the top plate. The plate was a 12 x 12. The house was built on a slab and the 1" J bolts went down into concrete poured in holes in the coral rock. They extended all the way up the walls and through the 12 x 12 top plate with steel plates and bolts securing them. No stink'n Simpson brackets back then. The whole place was built like that... massive timbers of Dade county pine bolted together. With no indoor plumbing, dry wall, electric or insulation a brief swim wasn't the catastrophe it would be today. It survived into the 70's when it was torn down to make way for a resort. :(
Sorry guys. I guess I am just stupid. Sorry for the confusion I have caused. Don I believe you have actually answered my question as well as ScottA.
There is no reason as to why 6x6, only trying to keep costs low and thought it would work as well as a built-up beam. Thanks for the drawing Don. It is the THING that brought everything together for me. Exactly what I have been thinking. I am in the middle of the State of Alabama so no biggie threat of hurricanes but there is some.
I don't want to get others, like engineers and government, involved in my project as that would only be someone with a hand out and a big possibility of "I really don't know, $500 please." I knew I could trust you guys to figure this whole thing out. As far as the load bearing wall, I would have to agree the wall between the kitchen/bathroom and living/bedroom would have to be load bearing for that great of span and, yes, there is a beam shown underneath at that point. According to the plans there is no vaulted ceiling. I am beginning to believe these plans are not true and complete as there is a lot of information missing that you guys keep asking me which I cannot answer. There is even no materials list - which goes back as to why I am working up the plans in BHG.
This conversation has taught me more than I ever thought I knew about doing this - which was nothing in the beginning. I feel like an idiot. Sorry guys.
Na that's not an idiot. I had this lady call me about not having any hot water once. I went to the house and she goes to the faucet and pushes the lever to the right and says "See no hot water". I pushed the lever to the left and said "There it's fixed. That'll be $75." Now that's an idiot.
There are no stupid questions. :)
Well -- OK ....granted there are some, but we are going to pretend that they weren't. While the rest of the world is watching TV and pretending it isn't stupid at least we can learn something. ........ [waiting]
By the way MountainDon, can I use curled wood like your drawing shows? J/K!!
As long as the 'curls' match and fit tightly there's no problem at all. ;D ;D ;D
These plans have little to no room for washer/dryer combo. I have actually squeezed my WD into what is suppose to be a linen closet. If I put a bump out ib the bathroom to give space to put WD would I need any piers below that? Not sure if WD wll be housed there or actually move shower into bump out.
Quote from: alcowboy on February 01, 2009, 09:54:13 PM
If I put a bump out ib the bathroom to give space to put WD would I need any piers below that?
You can build a cantilevered bump to accommodate that. The method used would depend on what way the floor joists are running at the bumpout. Easiest would be if the floor joists are perpendicular to the exterior wall at that point.
I think I'd prefer to bump the laundry rather than the shower, myself.
My W/D will be a very small operation, and crammed into the "Batroom". But then, I live alone, so the usage is less than for many.
I think someone is calling Batgirl.... [waiting]
the joists will run perpendicular to the bump. Thanks for the info and confirming the idea of putting the stack washer/dryer in the bump rather than the shower. So, basically, the "batroom" as it has been deemed will stay the same adding the bump to allow for a combo and I will be able to put the tankless water heater there instead as "decoration" on the bathroom wall. I plan on putting a curtain to close it off from the actual bathroom. "Pay no attention to the man behind the curtain!" Maybe I will even put up the green velvet curtains similar to Scarlett's famous dress ;D. NOT!
Quote from: MountainDon on January 29, 2009, 12:13:15 AM
(https://i133.photobucket.com/albums/q75/djmillerbucket/construction/beamsjoists.jpg)
I know this was just a quikie Don, and I am not harping on you, but when you joist up your floor, have only the middle section of the joists offset. That way, both ends will line up as a full sheet of ply on the edge of the joisting, and only the middle joists will need their plywood trimmed. In other words, your first set are on layout, second set lap the sides of the first so they are 1.5" off layout. The next lap should go back to layout. It's a little thing, but can get annoying. Also, if you can plan it so that there is enough overlap in your joists, you won't have to add nailers to your off-layout joists.
I may just be speaking Greek here...don't really feel like drawing a picture right now...tired, sorry!
:-\
Huh?
Now I am really lost...
That drawing was meant as a concept of principle drawing, not a construction plan. It probably would have been better to draw the joists for the side extension lapping on the other side of the central joists, the left side as drawn.
alcowboy, the best thing you could do before building, is get some good drawing paper. Use large enough sheets so you can make a large drawing that is easy to detail and draw in joists and studs to scale. That is what I did for our cabin and everything else I've built or remodeled before. I use 11 x 17" vellum tracing paper that comes in 50 sheet pads. they have a fine grid printed on the bottom side. It's available at good office supply stores. In the pad you can see the lines through the paper as guides and draw in pencil on the top surface. Vellum paper costs more but it is super erasable without rubbing and tearing away the paper surface.
Making an accurate scaled drawing will assist in understanding how lapping the joists at the center will affect the way the T&G subfloor sheets lays out. In making the drawing you will also see and understand how to adjust the joist lengths to account for the rim joist. That is, say the building width is 24 feet; you need to subtract 1.5" off each end where a rim joist will be nailed to the ends of the joists. Little things like that need to be thought out beforehand to avoid niggling problems later on.
The purchase of a good right angle drafting triangle and an architects scale will prove to be very useful. Mechanical pencils with 0.5 mm leads are my favorite pencil; they never need sharpening.
I find that making the drawing helps me understand how all the pieces will go together. I did the walls, the ceiling joists and the roofing all on paper first. I relate well to drawings; some don't, but it works well for me.
Thanks Don! All it amounts to then is be sure you have all measurements correct and know what the next step will be and how the next "building block" will fit into your current, etc, etc.
That makes sense. I have already gone one step further than the vellum. I have built a to-scale model of the home and have already seen how some of the "building blocks" should fit together. I have not done that with the subfloor though. Guess I will be purchasing some vellum this weekend. ;)
I've asked a question on the building inspectors website about pier and beam foundations and was referred to the appropriate code sections. To build a code compliant pier foundation without resorting to an engineer a pier and curtain wall foundation type is used. This is a rough sketch of what the minimum foundation for this house would look like using concrete block piers, brick curtain walls, and continuous footings under load bearing walls. It would be prescriptively allowed in non seismic areas. They are attempting to give a generic way to adequately support and brace the structure. To step below their minimums one should consult an engineer. There are other ways to build a well braced foundation, this is about the prescriptive minimum in masonry.
(https://i180.photobucket.com/albums/x109/windyhilll/piercurtwall.jpg)
Thanks for the info Don.
I've tried without luck to find any code info for pier and beam foundations. Do you have a link to any online info?
Is the concern racking of the piers? (I think that's the right term)
Seems like the compressive strength of either concrete or masonry piers are hundreds of times stronger than the weight of the house sitting on them.
I calculated the load of the 14x24, and using 8 piers with 2'x2' footings it seems to me that even with 2000 psi. soil there is plenty of bearing capacity. ???
So would the full perimeter footing would be just to support the curtain wall?
If a house were subjected to winds strong enough to topple steel reinforced concrete piers, wouldn't the rest of the wooden structure be reduced to splinters?
I'm not trying to question your info, or John's designs here. I wouldn't even pretend to know enough to do that. I would however like to find out all the info I can though about the foundation of my house, any areas of weakness, and if/where I could beef them up.
My County Development Division (high faluting name for building inspectors) routinely approves pier and beam foundations in the mountain area where my cabin is located. Many of these approved plans are not engineered per se, or even drawn up by architects. The office does look at the proposed plan and indicates what changes might be necessary to gain their stamp of approval. From talking with ordinary folks around there as well as some county officials the foundation changes usually revolve around the size of footing, the spacing of the piers or the size of the beams; some folks submit self drawn plans with inadequate footings, too few piers or undersized beams.
So maybe that doesn't meet any prescriptive code. However it is an approved foundation in my county. It is similar to many foundations around there that were built a couple - three decades and longer ago; foundations that still quite adequately support many buildings in this area. In fact my foundation is a vastly more robust foundation than that used for a 60 year old cabin just off my south property line. I've been in that cabin and the doors still open and close, the windows rise and fall and the floor does not sag. Back then it was built outside of any regulations.
So, it's my opinion that a building code that requires a full perimeter continuous footing for constructing a simple cabin like mine, is a building code that is out of touch with reality. More than likely, it is a building code that exists to extract fees simply for the need to justify its own existence. No doubt a cabin built to those prescriptive rules would not be likely to fall down. However, local experience here would indicate that pier and beam construction can be executed with great long lived success.
I do believe that building departments do have their place. Sometimes out of pure ignorance some self builders do truly dumb things, like a neighbor back home who removed an interior load bearing wall in a remodel. However, it seems to me that in the past decade or so, many prescribed changes to the codes are pressed on us because the code officials have run out of real things to do; they need to justify their existence. Many changes are also pressed on us because some special interest group, such as a manufacturer of a product, wants to see his product mandated as necessary to meet code. I believe that it is impossible to protect the citizenry against all possible things that could go wrong and some things are not very cost efficient.
I also believe there are too many government agencies involved in too many aspects of private life and they should butt out, but if I said that I'd be creating more topic drift. I wouldn't want to do that.
On the other hand when someone comes along here on the forum wondering anew about how something can be or should be done with respect to building one of the first things I ask is "are you subject to any building codes or rules?" I suggest that is the place to determine what the local officials require of their subjects.
Quote from: alcowboy on January 29, 2009, 08:52:16 AM
Sorry guys. I guess I am just stupid. Sorry for the confusion I have caused. Don I believe you have actually answered my question as well as ScottA.
There is no reason as to why 6x6, only trying to keep costs low and thought it would work as well as a built-up beam. Thanks for the drawing Don. It is the THING that brought everything together for me. Exactly what I have been thinking. I am in the middle of the State of Alabama so no biggie threat of hurricanes but there is some.
I don't want to get others, like engineers and government, involved in my project as that would only be someone with a hand out and a big possibility of "I really don't know, $500 please." I knew I could trust you guys to figure this whole thing out. As far as the load bearing wall, I would have to agree the wall between the kitchen/bathroom and living/bedroom would have to be load bearing for that great of span and, yes, there is a beam shown underneath at that point. According to the plans there is no vaulted ceiling. I am beginning to believe these plans are not true and complete as there is a lot of information missing that you guys keep asking me which I cannot answer. There is even no materials list - which goes back as to why I am working up the plans in BHG.
This conversation has taught me more than I ever thought I knew about doing this - which was nothing in the beginning. I feel like an idiot. Sorry guys.
I bought these plans as well and when you look at the side elevation the roof pitch changes further up the roof that the picture shows. This may not be a concern for others but I did not like the looks of the "plan" as compared to the picture. I did contact the seller and they offered to refund my money.
Quote from: new land owner on March 11, 2009, 02:51:29 PM
I bought these plans as well and when you look at the side elevation the roof pitch changes further up the roof that the picture shows. This may not be a concern for others but I did not like the looks of the "plan" as compared to the picture. I did contact the seller and they offered to refund my money.
I noticed the same thing and corrected that using my software. For the price I paid for these "drawings" I cannot complain. I consider them more as drawings rather than plans since they are not 100% accurate and leave off so much information. However, I have managed to reproduce the plans well enough in with the Home Designer Suite 8 that I can get started. I really need a software that would generate a better takeoff than what I have. I may play around with PlanSwift to see if I can get it to work properly.
I use Punch software ver 3000. It make it easy to see what the final product will look.
Here are examples of my plan for a 20 x 32 cabin
(https://i290.photobucket.com/albums/ll257/loonlakebound/1000FrontRight.jpg)
(https://i290.photobucket.com/albums/ll257/loonlakebound/1005ViewfromFrontDoor.jpg)
(https://i290.photobucket.com/albums/ll257/loonlakebound/1006ViewtowardsFrontDoor.jpg)
I am considering a 32x44 cabin located in North GA Mountains and I'm wondering cinder block pier foundation with wood floor joist. Wall height is 9ft 3in. What should my spacing being on my cinder piers