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Wall plates: a continuous run of timber?


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Just a quick one: does a wall plate (rim joist) have to be a continuous piece of timber? 

I ask because a visiting rep asked me if I needed the wall plate to be one continuous piece of timber.  Maximum uninterrupted run is just under ten meters. Nowhere in the architect's notes does he mention a continuous run of timber for the wall plate.

 

Thanks.

Ian

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3 minutes ago, Onoff said:

Here's one I made earlier:

 

SAM_7245_zpsddb630ef

 

It's got galvanised expanded metal stapled to the underside to provide a key to the mortar.

 

.... and was CNC cut from steel and then galvanised to within an inch of its life ..... :P

 

Real question is how are you holding down the wallplates to the walls ..?? Are you glueing/bolting the plates to the concrete core ..? I'm not sure how you can use ordinary straps as you can't screw them tight to the concrete. 

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5 minutes ago, PeterW said:

 

.... and was CNC cut from steel and then galvanised to within an inch of its life ..... :P

 

Real question is how are you holding down the wallplates to the walls ..?? Are you glueing/bolting the plates to the concrete core ..? I'm not sure how you can use ordinary straps as you can't screw them tight to the concrete. 

 

:) Radial arm saw actually!

 

How about on a bed of muck first in Ian's case then backed up with resin studs?

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22 minutes ago, PeterW said:

[...]

Real question is how are you holding down the wallplates to the walls ..?? Are you glueing/bolting the plates to the concrete core ..? I'm not sure how you can use ordinary straps as you can't screw them tight to the concrete. 

 

Bolting to the core. BUT (here's where it gets interesting)

 

This post explains the problem: in essence fixing the wall plate to an outer surface is different to fixing it to the inner surface of the wall because on the inside, the concrete is just under the wooden 'sheath'. The outside of the block has 120mm of PIR between the wall plate and the concrete.

Durisol say: cut a 100mm core 50mm deep into the outer face, remove the PIR. Drill the concrete ready for the bar, put some resin in the concrete and put the threaded bar in. Allow to dry.  Plug the 100mm by 50mm 'core' with a cement and water mix: consistency - yogourt. Fix the wall plate.

 

Faff..... Comes to mind.

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22 minutes ago, recoveringacademic said:

 

Interesting. Why?

Same rule as the for the roof or chamber straps cover three joists or trusses

I think with the wallplate BC don't like to see a tiny piece on the end

As long as your smallest piece is 1300 or more you'll be fine

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2 hours ago, recoveringacademic said:

 

Bolting to the core. BUT (here's where it gets interesting)

 

This post explains the problem: in essence fixing the wall plate to an outer surface is different to fixing it to the inner surface of the wall because on the inside, the concrete is just under the wooden 'sheath'. The outside of the block has 120mm of PIR between the wall plate and the concrete.

Durisol say: cut a 100mm core 50mm deep into the outer face, remove the PIR. Drill the concrete ready for the bar, put some resin in the concrete and put the threaded bar in. Allow to dry.  Plug the 100mm by 50mm 'core' with a cement and water mix: consistency - yogourt. Fix the wall plate.

 

Faff..... Comes to mind.

I'd chech with building control Ian

Tgey may still want straps every 1800 and a mortar bed under the wallplate 

I put two steels acros my garage and the one I built for the neighbour I bolted the wallplate every 450 and were it leaped onto 420 of block work I packed it with slate Due to torrential rain

My wife met him for the inspection 

He pointed out that were the wallplate is in contact with masonary  it should have a  motar 

Joint under it 

Sort of glad I wasn't there 

Oh I knocked a truss clip down the cavity He also pointed out that I'd one missing

Thats the only thing he has ever pulled up on our build 

 

One more thing was he insisted that I used 4x3 wallplate on the house rather than the 4x2 I used on the garages

I ran this by the engineer as it would cause me to have to re jig things adding 25 mill to the roof height

His reply was both will do the same job

We used the 4x3 without really knowing why he was so insistent 

 

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4x3 is becoming standard - it's what I had to use too. 

 

A mortar bed is designed to take up the irregularity between the timber and the block work below. I can't see how you can do that unless you've got a copy or a photo of the  top wall plate detail ..?

 

and coring out the Durisol sounds a real faff - is that their only option ..??

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I think we may be confusing the application here, 

I assume @recoveringacademic is referring to the plate he is fixing to the side of the wall, not a plate he is putting on top of a wall. just to be clear but i could be wrong,

 

FWIW we bed our plates on as well, (the ones on top of walls) treated 4x2, concrete screws about every 500 and 1200-1500 long plate straps every 1500, but i think this is not what Ian is asking about

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13 hours ago, Construction Channel said:

[...]

I assume @recoveringacademic is referring to the plate he is fixing to the side of the wall, not a plate he is putting on top of a wall. just to be clear but i could be wrong,

[...]

 

I'm talking about rim joists - which are often -confusingly- called wall plates.:S

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Riiiiigght ....

 

Rim joist should be the depth of the joists they are supporting and a minimum of 47mm thick. This allows twist shank nails to be used to fix the joist hangers without coming through the back. 

 

I'm bemused by the Durisol use of "yoghurt consistency" cement to fill a hole in a vertical plane - it's going to run straight back out ...!!

 

if you wanted some structural strength to the Durisol then cast some concrete "plugs" in short lengths of 50mm waste pipe slightly less than the thickness of the Durisol and core the Durisol and insert one in each hole - it would spread the twisting load. 

 

Other option is a second row of bolts staggered with the first so you're at 400mm/c top and bottom of the rim joist. 

 

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Don't think they will work here but maybe helpful for others in future - we placed the wallplates when we poured the ICF with concrete. I had predrilled and fitted the bolts into the timber (think we used 6x2), was a case of laying on, levelling, pushing the bolts down, wiggling about, some taps with a hammer to ensure concrete encased the bolt, then tightening bolts when the concrete had gone off. Was strangely satisfying actually!

 

https://www.roofingsuperstore.co.uk/product/roofing-hook-bolt-150mm-including-nut-boxes-of-100.html 

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23 hours ago, PeterW said:

Riiiiigght ....

[...]

if you wanted some structural strength to the Durisol then cast some concrete "plugs" in short lengths of 50mm waste pipe slightly less than the thickness of the Durisol and core the Durisol and insert one in each hole - it would spread the twisting load. 

 

Other option is a second row of bolts staggered with the first so you're at 400mm/c top and bottom of the rim joist. 

 

 

What a brilliant idea......

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