In the planning phase for a storage shed.
Location: Houston
Size: ~12x16

I'm looking at site prep and would like thoughts on foundation.

I have ruled out peer and beam style.

Considering either a poured slab or gravel pad. Either approach the base would be compacted.

I like the pad approach for drainage and slightly more diy. I have concerns about settling and difficulty leveling in future. Also, I see most using 4x4 treated as a perimeter and I question the longevity of constant ground contact. The other option I was thinking was setting a concrete curb parameter, but at that point it would probably be more effort than a slab.

I am also thinking 10' flat roof style so the skids and floor joists would raise overall height, which would be an issue.

Going slab it's likely not a big enough project to make contracting out worth it, and it's a little more ambitious of a diy but I'm comfortable with the work.

Thoughts?

I went with a gravel pad with ground contact PT 4x6 perimeter. There's a thread I posted here about a backyard studio where you can see it during construction. As for the roof, I recommend having a pitch that at least meets minimums for asphalt shingles. Flat roofs are prone to leaks without more frequent maintenance. If you must have a flat roof, I would contract that out to a reputable roofer so it's warrantied for some period of time.

That was a good thread but pics aren't there anymore.

Morgan Sheds Aggieland 20years ago added a treated plywood floor to their framing for their all metal exterior shed that they trucked over into place, leveled on conc.blocks among the oaks on very volatile expansive clay soils and I have had NO problems, NO regrets, only maintenance is the 5-year get tree junk off the roof.

15 years ago, construction/mechanic son's DIY metal shed on gravel, compacted earth has flooded and always with the ants & humidity BUT can drive into it w/o ramps. Never again!

The slab may be overkill in that I would want it min. 8" above grade, ramped if riding mower goes inside BUT less likely to blow away if no trees protecting it all round. All metal exterior is key IMHO.

YZ250 said:

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That was a good thread but pics aren't there anymore.

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Weird.

barnacle bob said:

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In the planning phase for a storage shed.
Location: Houston
Size: ~12x16

I'm looking at site prep and would like thoughts on foundation.

I have ruled out peer and beam style.

Considering either a poured slab or gravel pad. Either approach the base would be compacted.

I like the pad approach for drainage and slightly more diy. I have concerns about settling and difficulty leveling in future. Also, I see most using 4x4 treated as a perimeter and I question the longevity of constant ground contact. The other option I was thinking was setting a concrete curb parameter, but at that point it would probably be more effort than a slab.

I am also thinking 10' flat roof style so the skids and floor joists would raise overall height, which would be an issue.

Going slab it's likely not a big enough project to make contracting out worth it, and it's a little more ambitious of a diy but I'm comfortable with the work.

Thoughts?

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I'm a little confused as you ruled out pier and beam but then say you want gravel and skids which is, by design, pier and beam. Personally, I'd build heavy pier and beam and do your gravel setup on blocks designed for the purpose. This will come with the downside of having a crawl space which animals can get to so make sure you button that up. If that is not an option then you should go concrete and build your shed directly on it like a house.

For the roof, I highly advise against a flat roof. It's ugly, it requires mod bit materials which are ugly, and the fact is, you don't need to do it if you are doing this from scratch. If you want somewhat flat, then build a gable roof with 2/12 pitch MINIMUM, ice and water the entire thing, and put arch shingles on it. Less pitch than this and you're back in the rolled roofing side. Ridge vent it and it'll be nice and cool and look super.

I was thinking EPDM continuous membrane for the roof.

I'm in a 50's neighborhood with other flat.low pitched houses so the look would fit in with others.

I did an 8-10" depth gravel pad that is about 4" above grade (because I got tired of digging in rock) with 6" metal stud floor framing. Floor will never rot out, but shed likely couldn't survive a move either.

If I had to do it over again, I'd pour some curbs or tiny piers and use treated 4x4 skids to lower it a bit.

I had a Timber Frames "Pole" barn in Magnolia. Think about how they build those....
1 - Layout all the 4x's column locations
2 - drill holes for the treated columns
3 - set the columns and begin to align/plumb them. You align/plumb them by stringing a series of 2x6's around the perimeter. (top of the bottom 2x6 was 3 ft above the finished (later slab) These square up the columns.
With this stage complete those columns can be cemented in place.
4 - 2nd set of perimeter 2x6 will really get the columns plumb. Continue until you reach the desired eave height. (NOTE you still haven't anchored or trimmed your column 4x's yet)
5 - My barn had wooden trusses. Set, anchor and NOW you can trim your columns 4x's. Frame & brace as needed.
6 - finish with wall framing. My barn had 2x4's running from col to col, on horizontal attached to the 2x6's forming an angle shape. My framing was done with a nail gun, but all my additions I used longer deck screws, which for under 3" is my preference.
7 - as part of this process you can add any desired interior framing for windows, walk doors, garage doors etc.
8 - Here's the beauty. The bottom set of 2x6's at your finish grade are essentially your formwork for you floor. If you want to be fancy Run any electrical conduits you need and stub up. Consider a few spares as plastic conduit is cheap. Bigger is better and these days isolate power conduits from potential Info (Coax, Cat6, or Fiber) conduits. Then pour your slab.
9 - Pretty much the easy part is done. Now just install your walls, roofing and trim. There are many mfg's that can cut sheets to the dimension you need, and provide you with trim and install details. If I had to do it over again, I'd for sure have 1" or thicker foam insulation boards under the steel roof panels. A lot of heat transfers thru the roof. And that's cheaper than foam and easier to install than insulation batts that need supporting (chicken wire, etc) especially when hanging upside down.

I for 1 am not a fan of skidded buildings. In 10 yrs the floor is rotten, and that's the exact place for all your little varmints. Also skidded bldgs require ramps for rolling equipment and steps for walk doors.
When picking your site, remember the top of slab should be higher than the highest corner of the adjacent land.
Good Luck.

Thanks for all the responses!

Still working on my plan. I reviewed my property survey and there are two setbacks from the property line: 5' main residence and 10' detached garage.

If I'm reading this correct they are saying the main residence can be build closer to property line that a detached garage?

If I did a proper slab (which I'm leaning toward), then I assume it would be considered a detached garage and need to be 10' from prop line, or is there a creative way around this?

Haha, in Aggieland this would be reversed in most cases but if an area has had fire problems with garages (storing gasoline, etc.) then this makes sense.

I agree a storage shed (with similar potential contents) would also have to follow that of a detached garage.
That said, only IF you needed the shed closer to P.L. you would visit (or phone) the city Building Department to learn about special SHED setbacks. The height of the Shed may come into play with both the city restrictions as well as your ACC/HOA.

Yes, the Fire Dept. not only weighs in on Plans Reviews but also authors CODEs and local amendments to them.