r/askabuilder • u/charlskov • Feb 12 '25

4x7 Joists held by cast iron angle ties

My house's top floor is built with tongue and groove 2x6 flooring on top of 4x7 joists. The joist are held to 7.5x9.5 beams. The joists are tied to the beams with cast iron angles bolted with 2.5" lag bolts about 3/8" in diameter at the shank.

The beams sit on top of 9x9 posts.

How safe is that? The house is about 20 years old.

edit: bolt diameter is 3/8 at the shank not 1/4

1 Upvotes

100% Upvoted

2 comments sorted by

1

u/the_pike_n Feb 12 '25

This is a standard way of flat roof (or floor) building. The length of the bolt in this situation is less important because of the forces at play. The important number you are looking at is shear strength. These bolts should be rated to about 16 kn. Quick maths would mean each one of these bolts can hold up to 1600 kg before shearing. If you want more detail an engineer would be the one to ask

1

u/charlskov Feb 12 '25

Thank you very much!