I ran into an interesting situation yesterday, and am curious how common it is.
I’m doing steel beams, I-joists, and roof trusses for a BUF 1 1/2 story house. When I did the quote I told them I needed bearing at the stairway walls.
Now they’ve ordered the thing, but are saying they’re not going to pour the basement floor until the house is under roof. So I can’t use those walls for bearing.
Their reasoning is that they want bottom adjustable posts to support the steel beams. They pour the pier pads for the posts, but leave the pads 4″ below the finished floor height.
When they eventually pour the basement floor, the adjustable part of the post will be encased in concrete. They’re afraid that the screw adjustments on the posts will back down on their own if they’re top adjustable ones. (I’ve never heard of this being a problem)
Two things about this seem ridiculous to me. First, pouring the basement slab after the house is built seems like it would take a lot more labor.
Second, not being able to adjust the columns seems like a bad idea. If the soil dries out and shrinks a bit, I would think some adjustment might be needed. I can’t imagine a house going 50+ years without needing SOME adjustment.
So I’m kinda curious how common this is, and if it’s a regional thing. This job is farther south than my usual customers, so it could be normal down there.
Above all else: Sky.
Replies
BH.
When I did my big basement remodel, dumping lots of steel under the house, I had to pour a pier and put in a solid steel column welded to a plate and bolted to the pier. And it was welded to a plate which was welded to the steel (I have about 15 of these total). If your piers are poured on good soil they shouldn't move at all, so adjustment should be unnecessary. I think what these guys want to do is ok, but feels a little hacky to me. I long to build a house from the ground up, not top down.
MERC.
Around here, pretty much all the basement floors are poured after the house is closed in. Probably a weather thing, I dunno. As long as you have a window big enough for the chute, it's no big deal.
The posts are usually set in place, and the floor poured around them. I can't for the life of me understand how someone could expect a post to adjust itself; even if you were worried about that, I think a welder would fix it pretty quickly.
To each his own, however.
Adjustable posts? Shrinking soil? What a nightmare!
Around here (Massachusetts), lally columns are solid, rigid and fixed. They bear on concrete pads -- typically 30" x 30" x 12" -- that are on firm, compacted soil below the basement slab. The only thing the slab might do is lock the bottoms of the columns in position.
The slab does help hold the bottom of the foundation in place. They might want to think about that before they backfill without a slab in the basement.
Al Mollitor, Sharon MA
I see a lot of new construction here where the basement floors get done after the house is framed and dried in. It is pretty easy with window access for the chute. Without chute access, I've seen them pump it.
Seems a little dumb to me, though. Doing the flatwork before any framing seems better. Nothing in the way. Furthermore, it keeps the floor framing from getting a big jolt of moisture it doesn't need.
On the other hand, from a schedule standpoint, doing the cellar floor later, enables the framing to begin sooner, and waiting until dry-in takes the weather out of the equation.
Hi boss: I always pour the floor after the roof is on for the simple reason that the pumbing ground work and the pour itself can be done even it is pouring rain. As far as the bearing goes, I usually use an adjustable post, leave it in until I'm ready to pour, then I put in a 4 inch square steel post the exact length I need.
Have a good day. Cliffy
Out here the pads (piers) are poured with the footings. If the soil's not good enough for piers probably it is also not good enough for footings. After the walls are poured the ground work can go in, steel including solid lally columns, with foot plates, are installed and framing can begin. We keep a sump pump hooked up from excavation forward. During warm months the floor can be poured anytime, but before mechanicals, when not in schedule conflict. In cold months the footings, piers, and floor sub surface need to be protected from frost. We usually close in and heat then pour the floor, which cover the piers by 4" and imbed the columns. Remember the floor pour will put a lot of moisture in the house for a while. We only use adjustable columns when absolutely necessary, and then only occasionally for renovation and remodeling work.