Wall plate strapping - alternatives?

[Moony8]

We are intending to have a new roof fitted to our 1950s bungalow - however I am unsure whether the existing wall plate is strapped sufficiently (or at all).

I have taken a look in the loft - but cannot see the tops of any straps along the length of the wall plate (although admittedly it's hard to see because of the loft insulation)

If there is no strapping - it will be problematic since the interior wall is already plastered and as such dropping a strap down the wall will mean punching through the coving on the ground floor and channeling out back to the brick/block - fixing the wall plate and then making good afterwards - this would affect every room in the house and will be very messy.

Obviously I cannot drop the straps down the cavity as there would be no way to fix them in place.

My question is - is there any alternative form of strapping available that is perhaps a little less intrusive - perhaps one that drills down through the wall plate and down the centre of the interior wall (kinda like long spring back bolts - or something similar)

Thanks

 

[^woody^]

Why does the new roof need to be strapped? Did the old one blow away?

 

[Moony8]

Given the extent of the work we are having done - we will need a second wall plate affixed to the first and as such this work will need to comply with current building regs.

The architect has advised that if the current wall plate is strapped sufficiently - then we can simply affix the new wall plate to it. If the existing wall plate is not strapped - then the new wall plate will have to be strapped instead.

The architect has specified 5x30mm straps at 1.8m centres in order to comply.

 

[^woody^]

What I was alluding to, is if the existing roof had been fine for 60 years or so, why would a replacement roof need to be any different?

Is this replacement significantly altered?

 

[Moony8]

Yes the new roof is significantly different. The entire roof is coming off and being replaced with a steeper one with gables (the current roof is hipped).

The only part of the existing structure that will remain is the wall plate and ground floor ceiling joists.

 

[^woody^]

Strap it to the gables and existing joists then. There are also gable roofs from the 50's that have not blown away.

 

[Diver Fred]

1950's property - doubt if the wall plates are straped to the walls. At that time wall plates were fixed down by either using Hook Bolts which the brickies put in the horizontal brickwork joints 2 or 3 rows down, with the threaded leg coming up inside the cavity or centre of the wall on a 9' wall. That should be about every 4 to 6 feet along the walls. Alternativly the brickies would build in a hardwood pad about every 5 or 6th brick joint, then the wall plate would be nailed down into the pad.

So you need to look for short length of threaded rod and a nut (probably 1/2 rod with Whit Nut) or with the roof off nail heads.

 

[^woody^]

At that time wall plates were fixed down by either using Hook Bolts which the brickies put in the horizontal brickwork joints 2 or 3 rows down, with the threaded leg coming up inside the cavity or centre of the wall on a 9' wall

Really? The plates weren't just bedded down then?

Can't say I've ever come across any of those.

 

[noseall]

Can't say I've ever come across any of those.

I have. That's because I'm old and have done a lot of demolitions.

 

[Moony8]

1950's property - doubt if the wall plates are straped to the walls. At that time wall plates were fixed down by either using Hook Bolts which the brickies put in the horizontal brickwork joints 2 or 3 rows down, with the threaded leg coming up inside the cavity or centre of the wall on a 9' wall. That should be about every 4 to 6 feet along the walls. Alternativly the brickies would build in a hardwood pad about every 5 or 6th brick joint, then the wall plate would be nailed down into the pad.

So you need to look for short length of threaded rod and a nut (probably 1/2 rod with Whit Nut) or with the roof off nail heads.

That's great thanks.

If the existing wall plate is secured using either of those two methods - would we be able to comply with existing building regs if we adequately secured the new wall plate to the existing without strapping the new one?

edit: Just been reading building regs approved document A - and section 2C36 appears to say that vertical strapping is optional if the roof is of a suitable construction, has a pitch above 15 degrees and is covered with tiles or slate.

NHBC document says a similar thing - that vertical strapping is only needed where the roof much resist uplift and where the weight of the roof itself is not sufficient to prevent uplift. Can anyone advise whether I have interpreted these correctly?

 

[Tentpeg1]

Moony8 - did you ever get an answer on the 2C36? I have a similar issue. the BCO wants wall straps, but it would be very invasive as the work is completed. I have interpreted the same as you around 2C36.

edit: Just been reading building regs approved document A - and section 2C36 appears to say that vertical strapping is optional if the roof is of a suitable construction, has a pitch above 15 degrees and is covered with tiles or slate.

NHBC document says a similar thing - that vertical strapping is only needed where the roof much resist uplift and where the weight of the roof itself is not sufficient to prevent uplift. Can anyone advise whether I have interpreted these correctly?

cheers
TP

 

[tell80]

Do it the BCO way - its the safe way.
Responding to Insurance work, I've seen roofs lifted and dropped after a storm - no straps were seen, no insurance was paid to the householder. The householders paid us.
Maybe they fought the decision but what I've seen and worked on was far more damage than just fixing or re-building a roof.

 

[phatboy]

Is fixing down with threaded rod chemically fixed into the top couple of courses of bricks acceptable? I vaguely recall being told it was... similar system to the 50's with the whit nuts mentioned above

 

[noseall]

Is fixing down with threaded rod chemically fixed into the top couple of courses of bricks acceptable?

No.

 

[Nige F]

Do it the BCO way - its the safe way.
Responding to Insurance work, I've seen roofs lifted and dropped after a storm - no straps were seen, no insurance was paid to the householder. The householders paid us.
Maybe they fought the decision but what I've seen and worked on was far more damage than just fixing or re-building a roof.

shame you never took pictures