Shed roof fixings help

paddymc1

Have block shed (9" Cavity blocks) and now going do shed roof, going use either box profile or tile effect but looking to see what fixings to use to secure a Ledger to back wall of shed using 2 by 5 for the ledger if anyone can give directions be great

Fine Cheers

So what substrate are you fixing the 5 x 2 into, is it the cavity blocks ? Any photos ?

jack of all

Hollow concrete blocks are a devil to get a structural fixing into, as the walls of the blocks are only about 40mm thick and in reality less as a rotary hammer action drill will blow out the back of the block face as it punches through. What I have seen done with timber plates fixed to walls is where a long bolt is passed through the wall and a large washer and nut run on outside. Doesn't look great externally, but your fascia and soffit might cover it up. If you could mark out your fixing centres on the wall it might be possible fill the voids in these locations with concrete to take a fixing as an alternative.

Lumen

I dunno much about block construction, but why would you use a ledger board rather than resting the rafters on a wall plate? (is "wall plate" the correct term in Ireland for the length of timber than runs along the top of a wall and bears the rafters?).