Simple Porch

[OlJarhead]

I was thinking today that I won't be getting my surround porch/deck built for at least another year and decided that I should build a simple porch to tide me over as well as house my battery box and solar power systems.  My thinking was that I could build a porch off the entrance to the cabin wide enough to allow the required room for my battery box as well as the inverter and chargers.

I'm thinking that something at least like the following sketchup I just did:


Perhaps 8 feet wide by 6 feet deep instead of the roughly 8x8 I drew here.

This would give me lots of room to put in a battery box on the right of the entrance (which I could vent outside using a dryer type vent in the battery box and maybe a louver style vent at the bottom if needed).

I'm thinking an 18" deep and tall box 4 feet long will give me room for 8 golf cart batteries ( I have 6 now) and will only then need the bottom (I'd like it raised slightly), sides and top.

Security for the batteries and power units would be enhanced by being behind a locked storm door and they'd be under a roof.  I could also install the Xantrex charger, AIM Inverter and Iota charger on a wall mount (shelf for Iota charger) and within easy reach for inspection.

While this might only be temporary I'd build it as if I'll never get the chance to complete the surround deck (just in case) so here's my thinking on building:

Pier blocks on pavers sunk 12-18" below grade with 4x4 posts like the cabin foundation.  Only, since I won't be carrying as much weight as the cabin I'm thinking a 4x6 beam on top of the 4x4's front and rear will hold the walls.  Then 2x4 walls on the sides and front with 4x4 posts along the cabin wall to hold a beam for the rafters.

Bascially a shed roof from a 4x6 beam on the cabin wall (on top of 4x4 posts) to the 2x4 wall in the front and then 2x8 rafters on 16" centers.

I'm thinking I can go with 9 feet at the cabin wall side and 7 feet at the front of the porch giving me a 4:12 pitch (2 foot drop in 6 feet) with 5/8" OSB roofing and metal roof to match cabin.

I'd put in a 12" overhang all around

I think I can find free aluminum windows or real cheap anyway to give me some 4x4 windows on the sides (or maybe just one on the west end leaving the east walled for power systems) to allow light in and be able to see out of (or into).

Then stairs up to the porch from grade (about 3 feet).

Thoughts?

[Edit - I redrew with 6x8 porch - 6 feet deep by 8 feet wide]

[OlJarhead]

Another thought I had was that I could insulate the porch and even though it will only be 2x4 walls it should help quite a bit in the coldest part of the winter in keeping the cold out and the warmth in.  That, and the batteries might stay a little warmer.

This would give a place to leave boots etc when coming in out of the rain/snow also and with the added benefit of installing solar power systems in the porch so I don't have to build a separate box for them right now  -- which I have been fighting with since we could get a lot of snow and I need to be sure they are well protected.

Anyway, I think this could go up quickly as it's pretty simple in design and it would be pretty cheap since the components are all small in size and quantity.

[OlJarhead]

In working on this today I've come across a dilemma 

Since I don't want to hang this porch off the cabin wall (long story that Don and John might recall) I'll be building the foundation separate from the cabins and building 3 or 4 walls for the porch -- 4th wall would be framed but not sheeted if built at all.

I've been thinking that it would be easier to use three 4x4 posts and a 4x6 beam across the back wall (against the cabin) instead of a fully framed wall but then began to scratch my head as to how I'd tie in the side walls to it?

I just figured that with three 4x4's spaced at the ends and one just off center (right side of door) with a 4x6 beam running across them I'd be able to sit my roof rafters on that beam and then on the wall opposite of it and wouldn't have to worry about a header over the door etc.

But I'm wondering if I should just frame the back wall with 2x4's and put a header over the door that goes into the cabin anyway -- the thing is, that makes a 3 1/2" 'tunnel' between the studs and the door itself and might be kind of silly, whereas with the posts it won't look as odd.

Also, would a 4x6 beam be enough to sit the 2x8 rafters on considering the longest span is just over 4 feet?  Or should I just put in 4x8 beam instead and not worry about it.

I plan on using 2x8 rafters on 16" centers because I feel that it's a small porch and with a 4x12 pitch the snow should get pushed off by the much steeper roof pitch of the cabin.

Anyway, I'm still working on details but it seemed that incorporating the posts along the cabin wall would make the most sense to me...thoughts?

[OlJarhead]

Rough idea of what I'm talking about with the roof and front of porch hidden

[rick91351]

What is your snow load per code in your area?  I agree a small porch is not much of a factor but the rest of the roof might be.   How much drop are you looking at between the existing roof and the lean-to porch?  Is this a side that does not attract much snow?  Like a windward side or a side that catches a lot of sun?  If it is a side that you are looking at those two or three foot chunks of solid ice ripping down off there you might consider raising it up to the existing roof line.       Or maybe a gable front, that would best keep the snow away from the door and any sliding off the roof would split to the sides.  You would just extend a cricket to the existing roof.

[OlJarhead]

What is your snow load per code in your area?  I agree a small porch is not much of a factor but the rest of the roof might be.   How much drop are you looking at between the existing roof and the lean-to porch?  Is this a side that does not attract much snow?  Like a windward side or a side that catches a lot of sun?  If it is a side that you are looking at those two or three foot chunks of solid ice ripping down off there you might consider raising it up to the existing roof line.       Or maybe a gable front, that would best keep the snow away from the door and any sliding off the roof would split to the sides.  You would just extend a cricket to the existing roof.

The 12x12 pitch sheds snow like greased lightning   So I don't see that being an issue.  This is will be on the South side which tends to get enough sun in the afternoon to melt some of the snow on the ground and indeed can melt off all the snow more then a month earlier then the North (shaded) side.

I planned on starting the 4x12 pitch of this roof one foot below the overhang of the main roof, so my thinking is that any snow coming off the 12x12 will just keep right on going off the 4x12 -- though it might build up a bit more then i expect too -- have to wait and see.

[Redoverfarm]

OJ just to give you some idea.  This was early in the season and by the end of the snows there was about 2-3 feet between the top of the snow and the soffit.  This came from a 10/12 pitch onto a 4/12 pitch (porch 8' X 32') .  The snow shot out into the yard about 20' when it came off.

[rick91351]

OJ on the south side you most likely will be all right.  I think however I would do anything to help 'part the waters'.   Just a little less chance of having to spend a day digging yourself into your cabin.  Especially if it is half - three quarters ice.

     

 

[OlJarhead]

OJ on the south side you most likely will be all right.  I think however I would do anything to help 'part the waters'.   Just a little less chance of having to spend a day digging yourself into your cabin.  Especially if it is half - three quarters ice.

     

 

I think I get what you are saying -- with a gable front the snow would land on either side of the entrance and 'part' on the pitch of the porch roof.

However, I will have to think about how to do that without cutting into the existing structure because I want to be able to take down this porch in the future when we are able to build the surround porch.

My thought went so far as to screw on the sheeting/siding so that when it comes time to pull it down I could, in theory, at least unscrew the sheeting and perhaps save it.

I know it's a stretch and a lot of work, but at the present it could be as much as 2 or 3 years before we can finish the project with the surround porch (since I'm out of work now).  And with the pending winter expected to be a wet one I'm told that the 1 or 2 feet of snow we've gotten the last 4-5 years is likely to be about half what could accumulate this year.

Mind you, the neighbor tells me that's accumulated and not in one dump.  We're in a dryer climate so it's unlikely (though not impossible) to see much more then 18" at once.

I figure that with 2x8 rafters on 16" centers sitting on the wall in front and the beam in the rear it should be strong enough but I like your idea also and since the ridge would break up the snow coming off the steep roof it may be the best idea.

I'll take a crack at drawing it -- you've got my creative juices flowing now

[OlJarhead]

On a side note this shed has stood for several years (anywhere from 3 to 7 or more) and while the 2x4 rafters have sagged a lot it demonstrates why I think 2x8 rafters would hold up for a while.

Now off to draw the new design

[OlJarhead]

OK done

So, to do this I'd need to put in a post on the end at the cabin and beam it across to the front wall of the porch and then set rafters to each side from there to the walls on the east and west.  This will give at least 6" overhand on the porch as drawn -- though I could make it a foot) on the sides and 12" in front to cover the porch and 'part the waters' of the snow coming off the 12x12 pitch keeping the load on the porch roof light.

I'd have to tie the 4x4 post on the cabin wall to the side walls to keep it stable I think, and set it right on the post under neath the floor which sits on a pier block to ensure plenty of support but I think that wouldn't be too much to ask.

Flashing might be a bit of a bear but perhaps I wouldn't have to flash since I intend for this to be temporary (no more then 2-3 years if I'm lucky).  Perhaps a very good silicone sealer and thanks to the 12" eves above it won't get too wet anyway.

Thoughts?

[OlJarhead]

One problem I realized I'm facing is that the 9 foot height I was planning on for the pitch on the porch roof might not work.

The cabin walls are 10 feet tall and the rafters overhang 12" -- so I have to factor in the drop and think about what that does to my design.

One thing I could do is drop the porch floor 7" below the cabin floor and have one step up into the cabin without needing a stair.  This would enable me to build my porch walls at 7' with a 9' pitch and keep the pitch at least 7" below the 9' mark on the cabin walls.

Make sense?  Thoughts?

[rick91351]

That is more what I would do.  However if it is just a semi or a temp thing anything will work.  I just hate to do something thinking some day .... then as the song says 'someday never comes' and you are stuck with .... if I just would have.  Something that simple and easy you might just throw it together in the evenings at home.  Then run the dog gone thing up there on a trailer or in pieces parts!

Are you from around Tri-Cities?  

[Redoverfarm]

OJ since it is going to be temporary you could use a shed roof and put your entry door to the one side where you have the window and then put a window in the location that you were going to hang the door. Make sense.  Just make sure you get the proper door swing which looks to be a left outswing or in right inswing.

[OlJarhead]

That is more what I would do.  However if it is just a semi or a temp thing anything will work.  I just hate to do something thinking some day .... then as the song says 'someday never comes' and you are stuck with .... if I just would have.  Something that simple and easy you might just throw it together in the evenings at home.  Then run the dog gone thing up there on a trailer or in pieces parts!

Are you from around Tri-Cities?   

Live in the TC's but not from them....sorta from all over.  I've been here 8 years now though and my wife is from here...you?

[OlJarhead]

OJ since it is going to be temporary you could use a shed roof and put your entry door to the one side where you have the window and then put a window in the location that you were going to hang the door. Make sense.  Just make sure you get the proper door swing which looks to be a left outswing or in right inswing.

Another good idea -- geez

OK so if tomorrow never comes.....I have to think about that one too because I think it was sage advice.

Both good ideas though so now it's time to consider them internally and seek the inner framer in me

[MountainDon]

insulating the shed:  I don't think it would make enough of a difference to cabin temperatures. If it was facing north, maybe more so. I can't prove any of that, it's just a feeling.

insulating = warmer batteries. Maybe. However, when the place is sitting empty with nothing going on at all I'm not sure. Again, no proof. But batteries sitting there not having any chemical heating from use/charging don't have a lot of heat to retain and will slowly fall in temperature. Their mass makes their temperature fall and rise swing slow down. 

How permanent will the temporary porch be?  I would be strongly tempted to do a gable roof over the entrance just to keep the snow off the approach. Also to keep rain away, of course a gutter will help with rain.

If there is much snow involved I would be careful sizing the porch rafters and all. Snow will tend to build up on there more than on the 12:12 roof. It will also slide off the 4:12 just not as readily as the main roof. Our cabin 5:12 (5.4?) roof holds snow quite a bit before it slowly slides on a warm day. It the cold days of winter it held a lot.

Even an open sided, but roofed porch makes a good spot for shedding snow/mud before entry to the cabin.

I don't follow the reasoning behind trying to keep the porch gable ridge below the 9 foot mark? As long as there is room to get the materials in place I'd think the ridge on the porch roof could be higher.

I was also thinking like John, in that placing the door on the side of the porch could help with a shed roof design. But then that places the door under/near the 12:12 pitch roof edge and the snow slide off from there. 

[OlJarhead]

Thanks Don I appreciate your input.

My neighbor tells me his porch can get to 60 degrees during the day due to southern exposure but loses it all at night -- thus insulation might help keep the solar hearing in the porch at night and keep the batteries from freezing -- that's my hope -- and why I'd want big windows.

I'd have to have SOME window (s) on the South side of course and the West wall would catch the late day sun.

The 9' ridge height was a guess on my part and not hard and fixed -- I just figured having the ridge of the gable design coming to the eves of the 12x12 roof would ensure the 'dividing the waters' sort of effect but not be so high as you be connected -- of course snow backing up the wall could also be a concern but I think less so.

My real challenge is getting enough of a pitch that the snow coming off the 12x12 pitch will keep on going off the gable.

I like the gable design and it seems easy enough to build.  With the door to the south it will have less snow and ice build up and with a 12" overhang at the gable will be relatively clear of snow up the steps.

I think anyway

[Shawn B]

The cabin I used to live in, in N.W. Montana had opposing gabble roofs and at least every other spring/summer the landlord was up there repairing the ridge cap. Snow and ice would build slide down and pound the heck out of the ridge cap and the main cabins valleys. After noticing that I'm a firm believer of gable roofs dumping on shed roof. Of course you can always add snow brakes etc.

[considerations]

I have a 3/12 shed porch on the east (lee) side of the cabin.  The 12/12 roof dumps the snow on the porch roof...full stop.   Just to give you an illustration of what does not work. 

I will fix the slope, but like some have said, the "temporary" porch roof is up and I've not gotten back to it.

[OlJarhead]

OK Question:

Any reason to use a beam bigger then 4x4 on this porch?  It is 6 feet long and 8 feet wide, the beams will be on the 6 foot side and allow for a 6" overhang of the floor joists.


Like that

I also think I can get away with joists on 24" centers with 3/4" T&G osb subfloor.

Walls will be 2x4 with sheeting and siding and roofing will be 2x8 rafters with 2x10 ridge board with the rafters hung on ~14" centers (yes I know that's odd but it works well).  I'll install collar ties on every other rafter pair as well as rafter ties to make the roof strong and keep the walls from blowing out.

It's just a porch and while I don't plan to keep it forever I also don't want it sagging/crashing/failing on me.

Thoughts?

[OlJarhead]

On a side note this site: http://www.awc.org/calculators/span/calc/timbercalcstyle.asp?species=Douglas+Fir-Larch+%28North%29&size=2x6&grade=No.+1+%26+Btr&member=Floor+Joists&deflectionlimit=L%2F360&spacing=24&wet=No&incised=No&liveload=40&snowload=-1&deadload=10&submit=Calculate+Maximum+Horizontal+Span#answer

Shows DF#1 or betters can span 8'10" on 24" centers with a 40lbs live load and 10lb dead load.

So I'm thinking I can hang the joists on 24" centers for the porch and be fine.

No.2's show 8' 0" spans with the same dataset so I'm thinking I can frame the floor with DF#2's on 24" centers and hang those on 4x4's (still searching for that) and it will hold fine.

Where's DonP when I need him? haha  or MountainDon?
Erik

[Don_P]

If you're asking if a 4x4 would work as a beam at 3' spans bearing floor and roof, it depends on the roof load. At 100 lb/square foot total its cutting it too fine. A double 2x10 makes it without the midpost at that load. For a beam "deeper is cheaper".

On the same awc website find the "WSDD" Wood Structural Design Data book. Chapters of wood beam safe load tables.

If posts were extended through the walls the wall sheathing acts a post bracing...

This is my simple beam calc.
http://www.windyhilllogworks.com/Calcs/beamcalc.htm

[OlJarhead]

If you're asking if a 4x4 would work as a beam at 3' spans bearing floor and roof, it depends on the roof load. At 100 lb/square foot total its cutting it too fine. A double 2x10 makes it without the midpost at that load. For a beam "deeper is cheaper".

On the same awc website find the "WSDD" Wood Structural Design Data book. Chapters of wood beam safe load tables.

If posts were extended through the walls the wall sheathing acts a post bracing...

This is my simple beam calc.
http://www.windyhilllogworks.com/Calcs/beamcalc.htm

So double 2x10's on two posts instead of 4x4 on 3 posts.  Hmmm...let me do the $$ math and see what that works out at.

Thanks!

[OlJarhead]

If you're asking if a 4x4 would work as a beam at 3' spans bearing floor and roof, it depends on the roof load. At 100 lb/square foot total its cutting it too fine. A double 2x10 makes it without the midpost at that load. For a beam "deeper is cheaper".

On the same awc website find the "WSDD" Wood Structural Design Data book. Chapters of wood beam safe load tables.

If posts were extended through the walls the wall sheathing acts a post bracing...

This is my simple beam calc.
http://www.windyhilllogworks.com/Calcs/beamcalc.htm

Great advice and info!  I dropped about $20 off the pricing by dropping 2 pier blocks the 4x4 DF#2's and 2 4x4PT's.

Funny how something like this can make such a difference.

Thanks!