building an enclosed lean-to

[toolgirl]

Starting to build an enclosed 5' x 11' enclosed lean-to mud room. This will be built onto 2 existing exterior walls of home... so I will only need to construct 2 walls and the roof. I will be pouring a cement slab. Do I need to use posts or can I just use 2 x 4's to secure the structure?

[HayZee518]

is your slab going on the ground level? are you in a high frost - freeze area?

[toolgirl]

The lean-to is on ground level. Michigan is high frost area.

[HayZee518]

ok, then I'd advise you dig down and put in a layer of 2 inch foam beneath the slab. around the edges pour a footing below the frost line to keep the foundation from shifting due to frost heaves. put foundation bolts in the pour so you can bolt the plate to the top of the concrete when it's cured. use a layer of poly foam between the plate and the concrete. use pressure treated for a plate and I'd go with 2X6 not 2X4. stud up your wall(s) in one piece then lift it into place and fasten to your existing wall after it's completely plumb with 16p spikes. do the same on the other wall. after it's square ( measure from corner to corner with a tape or string) nail together.

[HayZee518]

lean to extension

try this diagram and see if it works for you.

[driz]

Wouldn't a floating slab work for that???

Hell around here everyone just puts em on a bed of sand and lets em float. I did my old garage 24 by 32 like that sitting in a low wet spot. Spread 2 loads of sand in the hole and used a thicer sides like 16 " by a foot something I got in a book somewhere and plenty of rebar and mesh. Not a single real separated crack since 1988 and it was poured under horrible half ass conditions. With no help but a bottle of Vodka. Its held up to -42F and Northern NY's frozen swamp conditions. Personally I now prefer just doing a pole barn with p treated posts as its lots cheaper and easier for something like a shed. Of course digger around here is not a shove sort of thing, big backhoe only.

[WVslottech]

ok, then I'd advise you dig down and put in a layer of 2 inch foam beneath the slab. around the edges pour a footing below the frost line to keep the foundation from shifting due to frost heaves. put foundation bolts in the pour so you can bolt the plate to the top of the concrete when it's cured. use a layer of poly foam between the plate and the concrete. use pressure treated for a plate and I'd go with 2X6 not 2X4. stud up your wall(s) in one piece then lift it into place and fasten to your existing wall after it's completely plumb with 16p spikes. do the same on the other wall. after it's square ( measure from corner to corner with a tape or string) nail together.

I thought you were an electrician?

[HayZee518]

I am. But its called multi-tasking. I built a 15X17X 1 1/2 story addition onto my house in northern ny. Dug by hand my foundation, made my own concrete forms and built my addition walls. Have a 5-12 pitch on my roof.

[WVslottech]

LOL.......is that what they call it??