BUILDER DISPUTE
What’s the best type of foundation system for small additions (20′ x 28′ Kitchen / Nook ) & (16′ x 18′ 4 Season Room opened to home ) just a straight trench poured (below frost line) to ground level with 8″ blocks to framing or a formed pad footing with poured foundation to ground level than the blocks ?
Is the padded / foundation wall worth all the extra digging, ( labor/ matl. cost ) or are they suited better for deep crawls & basements ?
How to finish & insulate inside the crawl space, underside of flooring, block walls & soil surface if no slab is being used ?
Which is preferred crawls or slabs ?
Guess I’m looking for the best solution for a foundation for small additions here in Michigan.
Builder wants to use a poured straight trench type foundation wall (NO pad footing under), poured to ground level with 8″ blocks to framing.
Crawl space / No slab, covering soil with poly & pee -rock , 2″ foam board around interior of block wall.
No insulation in joists / sub-flooring ??????
Your opinions & advise would be appreciated.
Replies
There are many regional differences and each town inforces building code differently and/or is more or less strict than the code as published.
Simply digging a trench and pouring concrete in it is cheaper than forming for footing, stripping the forms after the pour and whatnot. However I can't imagine that your frost line is so shallow that a simple trench is a good idea. In most areas a 16" wide footing is minimum and pouring a 16" wide trench with 4' of concrete is wasteful and shows a lack of professionalism rather than any kind of best practice.
It's more or less standard practice in most areas to form and pour footers with the width defined by soil load bearing ability - rebar is specified more or less based on the total load and width of the footing - and the amount and location of steel in the stem wall is dependant on loading and earthquake activity in your area. Some areas with problem soils will have more strict requirements than other locations. How is he determinining the footer width?
Concrete block is never as good as a poured wall and probably is more a factor of your contractor not having access to proper forms.
I don't live anywhere near your region, but many things your contractor wants to do don't seem like good ideas to me.