slab for shed questions

[Alan McKay]

Hey folks,

I live in an area that gets brutally cold winters. So cold that I cannot reasonably get below the frost line. Will it matter if I do not do things "right". The shed will only be 8x8 or 8x10 feet (undecided yet - one of the two)

I'm thinking back to my days with a summer job making sidewalks. This was in another area with winters not quite as cold as here. Maybe -20C where here gets to -30C and colder. Anyway, all we did for the sidewalks was dig up, put down a few inches of gravel, vibrate it down, then pour about 4 inches of cement into the forms.

Can I do this for my shed? Or should I put down the gravel, then vapour barrier, then blue foundation insulation, then the 4" of cement?

Do I need the trough with deeper cement around the perimeter when doing such a small slab?

[Joseph Meehan]

Check local codes first. Local soil conditions and weather make a big difference, which is one reason we have local codes for such things.

[m Ransley]

For that size shed it is normal to use apx 9 concrete blocks 3 on each side and 3 down the middle and have the shed off the ground so in the summer moisture is not trapped and rot doesn't occur.

[Greg O]

I live in North Dakota and what you ask is done here all the time with buildings much larger tha yours. My garage is 24 ft x 38 ft., on a "floating" slab.The edges are about one foot thick with rebar. Your local codes will be the final answer. Greg

[George E. Cawthon]

Just pour a pad. It may evenually break, if you have soil that shrinks and expands with moisture and freezing, but a good gravel base will stop most of that. Pour the cement a bit thicker, 6" would be good but at least 5". And, use a 6 sack mix and definitely put down hardware cloth (like the 2" x 4" mesh used for fences) and support it on metal stakes so that it remains about in the center to 1/3rd from the bottom. Don't know why you are using the blue stuff? You plannning on heating the inside?

[Randd01]

If you go with a concrete slab you will have to lay a course of cinder blocks around the perimeter of the slab in order to keep the wood at least 6 inches from the ground. Unless of coure you pour a 12 inch thick slab and keep it sticking out of the ground at least six inches. For that size shed unless your putting very heavy things such as motercycles in it a pressure treat floor on blocks as stated above is much better.

[wegge]

[Chris Lewis]

According to Alan McKay :

I think we live in the same place Alan ;-)

8x8 and 8x10 structures are _under_ the building code/permit applicability minimum (100 square feet), so you can legally do just about anything you want. Above 100 square feet you need "real" footings, permits, et. al.

Unless I was getting obsessive about flooring, I'd lay 4-6" of gravel, compact it, and lay precast sidewalk slabs (eg: 30x30 or 30x36).

I helped do this with a cottage shed (same climate, in wooded area, about same size) in the mid 70's as the floor for a premade metal shed.

It's still perfectly fine. And _that_ doesn't have gravel under it.

Just make sure you anchor the shed.

[ivan]

This is what I did with My 8 X 8 shed and have never had a problem . Keep snowblower, lawnmower and a bunch of other tools in it with no sagging at all.

If I build on a slab they will tax My shed but on blocks they don't and living in Taxachusetts I already pay more taxes and fees than I care to.

Good luck Ivan

[barry martin]

Alan:

AM> I live in an area that gets brutally cold winters. So cold AM> that I cannot reasonably get below the frost line. Will it AM> matter if I do not do things "right". The shed will only AM> be 8x8 or 8x10 feet (undecided yet - one of the two)

Go for the larger one!

AM> I'm thinking back to my days with a summer job making sidewalks. AM> This was in another area with winters not quite as cold as here. AM> Maybe -20C where here gets to -30C and colder. Anyway, all we AM> did for the sidewalks was dig up, put down a few inches of AM> gravel, vibrate it down, then pour about 4 inches of cement AM> into the forms. AM> AM> Can I do this for my shed? Or should I put down the gravel, AM> then vapour barrier, then blue foundation insulation, then AM> the 4" of cement? AM> AM> Do I need the trough with deeper cement around the perimeter AM> when doing such a small slab?

When they built our shed (did it at the same time as putting on the addition -- was cheaper to have the contractor do it!) they just put down several cement blocks for support of the floor. The new shed is larger than the old on the same site; raised several inches off the ground.

Isn't normally get quite as cold here (eastern Iowa) as your -20øC (-28øF) but I've experienced that temperature.

- ¯ barry.martinþATþthesafebbs.zeppole.com ®

• Odd Shows: Raisin in the Empire of the Sun

[Alan McKay]

yes, i believe so ;-)

it's actually 108 sq ft for some odd reason (I called the city). For now I think I'm going to just support it on blocks mainly because my wife and I cannot agree on where to put it. Maybe in a few years will agree on a 'permanent' location and then we'll pour the slab ;-)

thanks for all the input folks ...

[Glenn]

"ivan" screamed at the top of his lungs

actually they will tax a shed if it exceeds 120 sq.ft. slab or blocks...................doesn't matter.

you say Taxachusetts..................but Massachusetts taxes are lower than other states in N.E. (except N.H. of coarse) that's why you all run to the border to buy your alcohol and cigs.

just a little tid bit of info for the misinformed!

[Chris Lewis]

Do take into consideration wind. A few years ago, a number of sheds went for walkies in a strong windstorm.

Anchor it down.