I am attempting to board out a portion of my attic space for basic domestic storage. Nothing very heavy, just Christmas decorations and the like.
The area I wish to board out is the span between two 8" x 3" timber binders, which themselves are supported at one end by a load bearing wall and at the other by an RSJ.
These binders support the ceiling of the floor below, which is attached to existing 3" x 2" joists. These joists are butted, and a structural engineer has advised they are not strong enough to support the new floor for storage.
The engineer advised instead laying new joists across the span on top of the binders.
What is the best way of attaching the joists to the binders?
- I am aware of joist hangars which I could nail to the faces of the binders - but there are several inches of roof insulation sitting between the binders and running parallel to them. Attaching the joists via joist hangars would require lifting, cutting and relaying this insulation, and probably replacing at least some of it. I'd like to avoid this if possible.
- I could attach the joists to the top face of the binders - but how best to do this? Could I use e.g. angle brackets (something like this) to support them? If not angle brackets then what is the appropriate fixing?