OK I’m pretty slow to pick up on things, engineer has tried to explain this to me a couple of times with no success, so thought I’d seek enlightenment here.
Not a professional by any means, but I have a fair amount of building experience
I’m looking at a design for a bungalow where the floor joists run from east wall to west wall, and rafters tails set on north and south walls, in other words, the ridge line runs parallel to the shorter dimension of the house.
In this situation, what is the best method for making sure the first floor walls don’t spread? best way to attach rafters to plates, or whatever they need to sit on? thanks for any help. Andy
Edited 5/9/2006 2:45 pm ET by andyb
Replies
If you were to make it a structural ridge, meaning the ridge acts and is supported like a beam at each end, the spreading you are speaking of is not a problem or consideration. In a simple bungalow structure, I think this is your easiest option.
Or, I think you could also do a raised plate detail, which means that you could put the attic floor joists in, put down your attic subfloor next, then run a plate around the perimeter to seat your rafters. In this second case the attic subfloor acts as a "skin" that would resist the tensile forces. The only thing is you need to anchor the plate very well.
Hope that helps
Do the plans show the rafters sitting on the top plates or do the plans show the rafters sitting on the top of the ceiling joists?
This is very common around here and we will sit the rafters on top of plate that sits on top of the ceiling joists.
It can also be framed like every hip roof that has the rafters sitting on the top plates where you double up on the last joists closet to the rafter and run small ceiling joists from the doubles nailed in with joists hangers out to the top plates and nailed along side the rafters.