foam insulation

[mvk]

hi all
I'm planning a small house and one thought was 4x4 posts 4' o/c. this would lend it's self to SIP's. I then wondered if I could sheetrock the post and then use 2 2" pieces of foiled foam. I would then lag 2x4 nailer's to that and reverse batten rough pine siding. Discounting the labor this would be cheaper than SIP's. My question is would there be any problems between the two pieces of foam. Or can I buy 4" foam.
Mike

[ergodesk]

Mike you can buy foam up to 48" thick.

George Hawirko
http://ergodesk.blogspot.com

[tjm73]

If you live in an area that does not have building codes you might get away with it, but I have to wonder if the material will be up to the task of supporting the weight of the roof (do you get snow?) and withstanding side loads (ie..wind).

There is a 24" o.c. technique that is getting a little attention. I woudl have to consult my guide, but I think 16" o.c. is required for code. 48" o.c. just seems too large to me.

[mvk]

Hi George and TJM73

George are you talking about SIP's or are you talking about just foam and what kind EPS or poly whatever. This whole thought train happened after I got some prices for SIP's from Winter Panel 4 1/2" structural panels $4.48 sf uninstalled I didnt get a price for installation. 2" atlas energy shield is about $.90 sf. So I thought if I used 2 pieces and added for Sheetrock, metal fasteners like Simpson's and 2by strapping I could get the same R value for about $2.50 sf not counting labor. About $4000 savings for the walls in materials and truthfully I think my days of installing SIPs are long gone so the savings would be greater.    

TJM73 I haven't looked at the code guess I should. As far as snow and wind about 25 or 30 years ago I built about 10 3 season porches with fir 4x4's as posts and toplates and 4x6's or 4x8's as rafters and 2x6 t&g for the roof deck. They had shed roofs and pitches that were between 4 and 2.5 nice and low to collect lots of snow and we used to get a lot of snow then. So I wouldn't worry about the snow myself. As far as wind loads if you used 4x4 braces between beam and posts just as with conventional post and beam construction I would think that that would work. If wind loads where the show stopper I could get some 2"x 1 1/2"x 3/16" angle and  bolt it to the top of the post and to the band Joist.  I wonder what a engineer would say.

Anyway I'm working on 24'x24' 1 1/2 story with living space upstairs more like spare bedrooms and a bedroom addition down stairs to be built later or maybe built as a enclosed porch with the house and hopefully I can get away with piers for that part. I would like to get some drawings up here and maybe get some ideas. I'm really impressed with a lot of the houses that I have seen on this site, and I got a few chuckles. Those dishes in the sink. I think that after 30 years I have permission for a open floor plan at least today.

One more think I don't know if this should be a new thread or not but. I have a green house with a 30 year old roll roof. It leaked last winter. This spring I sealed all they lap joints and any particularly worn place with mesh and patch and then coated the whole thing with roof coating. Just got a call from my tenant that it leaked again. I don't want to fix it till next summer. Anybody got any Ideas that can get me through another winter. There is a white elastic product its made for metal trailers anyone have any experience with that? Would it stick to roof coating?

Thanks again George and TJM73  


         

[glenn kangiser]

Check well around roof penetrations.  It could enter and run down to a different spot.  Henry's makes many different types of sealer.  There is one that will work on wet roofs and has reinforcement.

[peter nap]

What your building is in essence a pole building. The 4' spacing is a little close. My plans call for 12' OC 6X6 but I changed it (again) to 8' with 4X6 every other pole.

I'm not sure the SIP's would work and I know the foam wouldn't. Much of the rigidity the pole building has is in the Girds. On mine I am using 16' 2X4's progressively so every pole supports two poles forward.

You could use the SIP's panels on the outside of the girds but that would be expensive and overkill.

I am using spray insulation in the cracks, fiberglass between the girds and foam board in the 6" space between the girds and the inner wall.

In many localities, like mine, pole buildings on A1 property are exempt from code.

[mvk]

Thanks for the response

The product that I wanted for the roof was described to me as pouring on a rubber roof. I think I found it in Lowes and it can't be used on asphalt.

My original question about 4x4 posts maybe was not clear. If you go to John's greenhouse drawing and think of the whole building as the south wall and then replace most of the glass with solid wall that is what I meant. I like small posts and I was thinking of how to use foam cheaply. I plan to get some drawings up and maybe I will draw some details of what I had in mind. One of my concerns was what happens when you sandwich those pieces together, there would be 4 vapor barriers in the wall?

Thanks Mike

[glenn kangiser]

Could be but if the first one stops it there shouldn't be a problem plus vapor can't inhabit the same space as the foam.  Just my opinion.

[Jens]

How large of a building are you planning?  I think what you are talking about is basically a smaller scale timberframe.  The type of building that has been in use for centuries everybody.  Many people these days, especially in the building departments, seem to forget that many of these houses have withstood the test of time.  Timberframing is a very viable building method, and I personally don't see anything wrong with 4x4's on 4' centers.  Remember though, that your beams will have to be sized appropriately for the span, and once this is done your posts may then be undersized.  Most timber structures are built with 8x8's, or 6x6.  They usually have the posts between 8 and 16 feet apart.  An 8x8 is good for about 16' of span, if I remember correctly, and 6x6 up to 12 feet.  4x4 should be good for 8' or so.  You should have some shear bracing, and in timber construction this is handled by a "wind brace", or "knee brace", which cuts an upper corner at 45 deg, and connects the two pieces.  Plywood or osb could also be employed, but I seriously doubt the shear strength when the framing members are more than 24" apart, unless you could get a sheet big enough to cover your whole wall in one.  As said before, a pole building gets some lateral strength from the girts, which connect all of the poles at standard intervals, and this type of thing could be done on a timberframe as well.

[mvk]

Hobbyist you have said it a lot clearer then I can, and the beams are a problem.

 I'm still working on drawings. I'm a little intimidated by computers. I looked at the free drawing program and that's not for me. I want to do 1/4" and 1/8" =1' drawings on regular printer paper, scan them and then put them on this site. Will that work? Once I get the drawings up I would like to explore this subject some more.

I would like to get some information/ideas about site work. I have read some of the forum about this.

I need 400' to 600' feet of road, I will probably need a full foundation, and I can't do my own septic design/build in New Hampshire anymore. Subject for the rants!  When I talked to site work contractors before they wanted to give me a package price for everything, road, foundation dug and poured and septic designed and built $$$!  

I got a price for $750 to do the septic design 20 years ago anybody have an idea what it will cost now. I want to have my own design because I want to get bids for everything as a package and separately. I also need a elevation for the septic to get a elevation for the foundation.  

My drive way goes back pretty flat for 100' or so then it drops off pretty quick and then flattens out again all the way to the house site. I can get in and out easy with a four wheel drive but backhoe people don't like it much. It has been perked three times, once when we bought it and twice when we thought we were close to building. The tests were only good for so long. So the septic designer will have to perk it again.  

I don't think that we can start to build till spring of 09 but I would like to scrape together enough $ to cut into that hill with a dozer and make it easier to get in and out. It's a skidder road now. It looks to me as if a good size dozer could rough out that road in a day maybe two. I think I would then consider buying a old backhoe if I could, I think I could then dig the foundation, spread gravel to finish the road, this has worked for some friends off mine before. Anybody rent a dozer before to do it your self or have an idea how much it would cost. I don't have a lot of operating experience, none on a dozer I've used a backhoe some and I ran a big electric loader underground for awhile I got pretty good with that but it's hard to roll in a mine. Are there videos for cutting a road with a dozer? Also I say dozer and back when I still worked in construction you would have used a dozer, I'm told that they now use excavators on roads? Whats everybody's experience with this? Seems that they would be slow and I wonder If they are used because then you only need one machine on the job however I'm told that a good operator can do everything with one?
       
Foundation what to do? Most houses around here have full concrete foundations. Slabs are not to popular and they used to want a four foot deep wall anyway. We will have to get a mortgage and I was told that they were hard to get with piers? My wife is also against piers. I called around about renting forms and couldn't find any. Blocks have a bad reputation around here. The last time I used any concrete it was $47 a yard and $11.50 a lineal foot to set forms. Concrete is now $107 a yard. I think that my order of preference would to be to rent forms and pour myself, and then block foundation with concrete down the holes. They used to pour some lousy concrete around here and re-bar was never used in residential construction. There was also not much done about drainage so there are a lot of cracked leaky basements. Boy piers sure would take care of all those drainage issues and save a lot of money. Whats everbody think.

[MountainDon]

I want to do 1/4" and 1/8" =1' drawings on regular printer paper, scan them and then put them on this site. Will that work? Once I get the drawings up I would like to explore this subject some more.

I've done that many times. Scan, and size 'em to about 640 - 800 wide, upload to photobucket and paste the link into a message here.

You don't say what size of building, one floor or two?

As for block having a poor reputation, they're as good as the man doing the work, just like anything else, IMO.

As far as foundation types and mortgages, shop around with various banks and mortgage brokers. See what they have to say before you make decisions on what others say.

[Jens]

I don't know what part of NH you are in, but down here in the Seacoast area it is a pretty standard price to have the pit dug, foundation poured, backfill, and septic for about $20-25K.  I know that is a pretty steep sounding price, but actually amazingly low compared to some places.  Besides, foundations aren't exactly the fun part, and if you live a good clip from the land it might be worth it to just let someone else do it.  Where are you located?  Piers would be the easiest, but no, banks do not generally like them.

[mvk]

Thanks for the response Mountain Don and Hobbyist

I'm sorry for not responding for so long but I wanted to get some drawings before I kept talking. I'm close, I got some pictures of the land and one drawing on photo bucket and I put them on a blog. Don I think that I did what you said as far as scanning  

Hobbyist you responded
I don't know what part of NH you are in, but down here in the Seacoast area it is a pretty standard price to have the pit dug, foundation poured, backfill, and septic for about $20-25K.  I know that is a pretty steep sounding price, but actually amazingly low compared to some places.  Besides, foundations aren't exactly the fun part, and if you live a good clip from the land it might be worth it to just let someone else do it.  Where are you located?  Piers would be the easiest, but no, banks do not generally like them.

Hobbyist I'm west of Nashua and I live about 10-15 min. away from the site. $20-25K, I would guess that those prices would be about the same over this way. Add 400' of road and burying the electric and that would bring that up to $30-35K you think? My site is pretty rocky so could be more. Add well $5-10K? Adds up quick. Would you know how much of that $20-25K would be septic (ballpark I know they are site specific) and what is the going rate for forming per lineal foot plus cost per additional corners, interior footings etc. and how much per foot for wells over your way?      

So why do that part myself?

This will be our only house to live in so I would rather put the money other places. I would like to get a backhoe and do what I can before applying for construction loans.  I have the skills to do either a concrete wall or a block foundation whether my body could still do it I don't know.  I work half the days in a year  but  never  more  than  three in a row, and if I use my vacation right I could have seven days off every other week for a good while so I have some time. I would like to do as much as I can with my nineteen year old son, and I don't mind concrete work. I've never been  impressed with foundation work around here.  Don't know if I can pull it off but it seems that there is a big chunk of that $40K+ that is up for grabs.

Whats the thought on rebar, never seen it used in NH on residential construction, perhaps they do now that they have adopted a building code, though guys that I know who still work construction say they still don't. See it sticking out on all the cross sections of foundation drawings around the forum.

Thanks MVK                    

[glenn kangiser]

Even a couple #4 rebars in a footing helps keep it from separating if it cracks- more complicated requires more.

[John Raabe]

My suggestion on a poured concrete crawlspace foundation is to use two bars in the footing and one in the top of the stem wall tied to the anchor bolts. Keep the bars (#4 or 1/2"d) about 3" away from the top of the wall and bottom of the footer.

This will help the foundation work as a reinforced beam to span small settlement issues. If you are in heavy earthquake areas there may be a need for vertical bars.