You sheathe the walls first because if you put the trusses on before the walls are plumbed & braced, it's possible to rack the framing, and if the walls are not square &plumb,nyou won't be able to do it witth the weight of the roof in place.

They were adding sheathing to the walls. The sheathing provides rigidity to the walls; it keeps all those straight up and down wall studs from simply leaning over and falling down, all together. When that happens, it's called "racking."

Why don't you ask them? I would guess that they know what they are doing.

so would you rather have the walls on your roof.

We are having a house built, they technically started 3 weeks ago but it was only 2 weeks ago that we saw the first evidence of work. Digging for the foundation, pouring the footers, building the block foundation, etc took until early this week.

Wednesday (2 days ago) they put on the floor joists and sub floor. Thursday (yesterday) they framed all of the exterior and interior walls. It was nice today but it is supposed to rain tonight and tomorrow so I was expecting to stop by the house after work and see the roof trusses at least, preferably more.

But, they didn't even start the roof...instead they started on the exterior walls by hanging the same plywood type stuff on the exterior walls that they used on the sub floor.

I could be wrong, but it seems like the last thing you want to do without a roof is to put more coverings on the outside of the house to keep the water in.

So my first question is if this is normal...my second question is whether or not I should still expect the roof done tomorrow considering the rain? They told me on Wednesday that all of the framing including the roof would be done "by the end of the week" and I was just wondering if that was still realistic.

Thanks in advance for any answers.