Attaching rafters to ledger board and wall plate

[robinbetts]

Hi there,

I'm having our garage roof replaced (flat roof ~5 degrees), and it's a lean to against nextdoor's house. The roofer has fixed a 147x47 timber against the lean to wall as a ledger board, and a treated 97x47 timber on top of the opposite wall as a wall plate.

First question: They have screwed the 147x47 joists into the ledger board, two each side at 45 degrees, rather than using joist hangers as I had expected. Is this okay? Do the building regs say anything about how this should be done?

Second question: Both the new wall plate and the ledger board are fixed with what look like some kind of hammed in fixing, about 3/4" diameter at the head, but looks kind of hollow. Never seen them before. Any idea what they may be, or if they're okay to use in these situation?

Third question (sorry): The new wall plate has been laid on the old mortar bed and consequently there's a good 4-5mm gap between the mortar and most of the timber. Looks like there may be the remains of some old bent over nails coming out of the old mortar, and they've packed the gap in a couple of places with some bits of leading. How big of a deal is this? And if it is a problem, given the whole roof's been cut in now, is there anything that can be done? Also, wall plate hasn't been strapped to the wall. Is this necessary? We're in a pretty windy location.

Sorry for all the questions. I might just be being paranoid, but I want to make sure they aren't doing a bodge job!

Thanks!

 

[Alastairreid]

Joist hangers with twisty nails for sure.
They should fit 1200mm restraining straps ever couple of meters to the wall plate.
The wall plate should have been bedded on fresh mortar.

Whats the clear span from ledger to wall plate?.

 

[robinbetts]

Thanks for the reply.

I guess the hangers can be added now in addition to the screws? Not sure what can be done about the mortar bed...?

It's about 5.5m from ledger to wall plate, but there's a UB been put in about halfway, so the max clear span's approx 2.5-3m.

 

[Alastairreid]

Yeah was wondering about the span as the joists seemed a bit on the lean side.
The mortar bed is used to level and fix the plate in position then the restraining straps..the joists skew nailed to the plate.
No probs adding the hangers now.

 

[robinbetts]

So should I ask them to re lay the mortar? Not sure how they could even do that without taking it all off...

 

[Alastairreid]

Its not a biggy but i would keep an eye open for any other shortcuts they may take.