I have an ornamental thing over my garage door. Its made from 2x12 douglas fir with 21’ span. Each end rests on cross pieces bolted to a pair of 8x8 posts.
I occasionally put plywood on it to clean or work on the windows above the garage.
Yesterday i stepped on a beam end and my foot crunched through from rot. Rot under the paint. Rot extends 10” from end of beam, that beam end is in a soggy poorly vented area. Rot was concealed by a thick layer of paint so i hacked at it and found the two beam ends are lot of mush.
Anyway. Rather than replace all the wood id like to replace the rotted sections with a scab and support them with sisters.
I took out the closest cross brace and have got 24” of overlap for the sisters before the next cross brace which has no rot.
This isnt a public bridge - it really isnt even structural, but how should the sister be attached? I see a lot of different recommendations but they are for real load bearing like roofs, floors and parking garages. I dont mind doing it right.
Thinking 1/4” steel filch plate and 1/2” bolts in w pattern? How many bolts? 3 per foot? Is 2’ overlap enough? Can anyone point me to authoritative instructions for how this sistering should be done?
Also, id like to cap the beams. I see places selling little beam end covers but why couldnt i fab some full length beam covers out of sheet? My google foo is weak what is that sort of sheet fabbing called?
