Tie in cavity wall with block on flat?

dubber

Looking to build an extension and use cavity wall construction, it will be "in-line" with the main house (i.e. not perpendicular) which is block on flat. The cavity wall is 300mm total depth, the block on flat is 220, what is the correct way to tie these together?

Gumbo

dubber wrote: »

Looking to build an extension and use cavity wall construction, it will be "in-line" with the main house (i.e. not perpendicular) which is block on flat. The cavity wall is 300mm total depth, the block on flat is 220, what is the correct way to tie these together?

What does your engineer recommend?
There are various options and specific instruments available.

johnny_adidas

Pretty unusual to use block on flat, so just checking, it's definitely not cavity blocks or cast concrete?

dubber

I haven't asked the engineer yet as I'd like to be armed with information before asking him, all of the starter packs I've seen seem to be designed for perpendicular joins where both leafs can be tied easily to a wider existing wall. I'm not 100% sure it's block on flat, but vaguely remember seeing that last time the plasterboard was off.

Gumbo

dubber wrote: »

I haven't asked the engineer yet as I'd like to be armed with information before asking him, all of the starter packs I've seen seem to be designed for perpendicular joins where both leafs can be tied easily to a wider existing wall. I'm not 100% sure it's block on flat, but vaguely remember seeing that last time the plasterboard was off.

In fairness though, it doesn't matter what info you have or done have. The engineer will design the connection and the builder will have to do it. Otherwise the engineer will not sign off on it.

So imo, you are paying the engineer I presume, let him do his job.

Calahonda52

OP: can u take off a wall vent or internally to see what the block is, removing pb wont answer the question.

Dont u/stand what the orientation is to the existing.

If u are not butting the two new leaves to the existing wall then what....?

dubber

kceire wrote: »

In fairness though, it doesn't matter what info you have or done have. The engineer will design the connection and the builder will have to do it. Otherwise the engineer will not sign off on it.

So imo, you are paying the engineer I presume, let him do his job.

I just want to be sure he's doing a good job!

dubber

Calahonda52 wrote: »

OP: can u take off a wall vent or internally to see what the block is, removing pb wont answer the question.

Dont u/stand what the orientation is to the existing.

If u are not butting the two new leaves to the existing wall then what....?

Here's the layout, E = existing, N = new, P= new party wall with terraced neighbour, ignore the dots. The new cavity wall is wider than the existing wall, I'm just wondering what the best way is to tie these together.

EEEEEEEEENNNNNNN
.................................... N
...................................NNNNNNN
.................................................N
.................................................N
EEEEEEEEEPPPPPPPPPPPPP

Calahonda52

Why can't I join the dots, unfair:D

Is the party wall a new wall or is it one leaf of the new cavity wall?

Maybe edit it and add a few ccc for cavity and L1 for leaf 1 and L2 for leaf 2

Given that it is a party wall I presume you are up to speed with this

http://www.irishstatutebook.ie/eli/2009/act/27/section/43/enacted/en/html

dubber

Calahonda52 wrote: »

Why can't I join the dots, unfair:D

Is the party wall a new wall or is it one leaf of the new cavity wall?

Maybe edit it and add a few ccc for cavity and L1 for leaf 1 and L2 for leaf 2

Given that it is a party wall I presume you are up to speed with this

http://www.irishstatutebook.ie/eli/2009/act/27/section/43/enacted/en/html

P is a solid wall on the party line but not shared, they have a nearly adjoining wall on their side for their extension. I'll try to do a better diagram when I have some time, my main question is on the "exterior" side where "N" meets "E". Clear as mud!

johnny_adidas

Do you not have a line of existing e where the back wall is so there will be a nib of wall left which is perpendicular to the new walls? The wall starters would be fixed to this nib. It's a nasty junction though and it would make better sense for you to upload the engineers drawing of that area so people could comment

dubber

johnny_adidas wrote: »

Do you not have a line of existing e where the back wall is so there will be a nib of wall left which is perpendicular to the new walls? The wall starters would be fixed to this nib. It's a nasty junction though and it would make better sense for you to upload the engineers drawing of that area so people could comment

OK, there could be a nib there. If not, I suppose I could continue on the same construction method, then start the cavity wall at the perpendicular wall?