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https://www.askthetrades.co.uk/cgi-bin/yabb/YaBB.pl DIY Forum >> Building Questions >> How to tie in a wall https://www.askthetrades.co.uk/cgi-bin/yabb/YaBB.pl?num=1104741772 Message started by diydooer on Jan 3^rd, 2005, 8:42am

Title: How to tie in a wall
Post by diydooer on Jan 3^rd, 2005, 8:42am

I am currently living in a house where the previous owner converted (not very well) part of the garage to give a breakfast room. The outside wall he created by building a stud wall with an 8" gap between it and the existing outside wall, part filled it with polystyrene and 12mm plaster board.

I am wanting to change the stud wall into a thermalite wall with a 4" insulated cavity. The length of wall will be aprox 8ft by 8ft high.

How do I tie this new wall to the existing outside wall? Obviously with a new built the ties are placed in the brickwork as the wall goes up.

The existing spanwise wall was built from 4" concrete blocks straight onto the concrete garage floor. From what I can gather the floor was only built aprox 4" deep over hardcore. Do you think this floor can support the weight of a wall of this thickness measuiring 9ft wide and 8ft high? This wall is currently not load bearing.

Title: Re: How to tie in a wall
Post by Chaddy on Jan 3^rd, 2005, 8:18pm

Hi Diydooer.

Welcome to the forum.

I'm not a builder but you can get a 'wall tie pack' from screwfix, and all builders merchants. As far as i understand it, there is a metal strip that screws to your existing wall. To this wall ties can be fixed at the appropriate height to line up with the mortar joints in the new wall.

Hope this helps.

Title: Re: How to tie in a wall
Post by diydooer on Jan 3^rd, 2005, 9:42pm

Hi, Thanks for the reply. I have looked in screwfix but could only find the ties for creating walls perpendicular to an existing wall. I believe these are commonly known as 'firfix'.

Would you have an item code for the suggested item?

Title: Re: How to tie in a wall
Post by Chaddy on Jan 3^rd, 2005, 10:08pm

Just re-read the question. I first read it as you were coming off the external wall at 90 degrees!! ;D

So you want to tie in a new internal wall to the existing external wall?? ???

Title: Re: How to tie in a wall
Post by PowerTool on Jan 3^rd, 2005, 10:30pm

Don't know if there is a product commercially available,but it could be done by drilling holes in the mortar of existing wall,and placing metal rods (something about the size of electric arc welding rods with the flux knocked off) and insert into holes when new wall reaches same level.
As for the floor,believe 6" to be more normal,but is it reinforced or just ordinary slab ?

Title: Re: How to tie in a wall
Post by big_all on Jan 3^rd, 2005, 10:45pm

is it these your looking for ::)
http://www.screwfix.com/app/sfd/cat/pro.jsp;jsessionid=225QPARVJPZCJCJO2C3CIIQ?id=41317&ts=92250

or these
http://www.screwfix.com/app/sfd/cat/pro.jsp;jsessionid=225QPARVJPZCJCJO2C3CIIQ?id=41311&p=x4&ts=92333&destination=../cat/pro.jsp%3Fid%3D41311%26p%3Dx4

Title: Re: How to tie in a wall
Post by Chaddy on Jan 3^rd, 2005, 10:52pm

Big All these will work at each end of the wall but i assume ??? that the new wall is running parallel to the existing external wall and he is recreating the cavity wall but in blocks, and it is this that needs tieing in.

Diydooer dont know if it's feasible to use the screw in wall ties again available from screwfix? ???

Title: Re: How to tie in a wall
Post by Robbo on Jan 3^rd, 2005, 11:16pm

Can you not get the galvanised wall tie fixings in a " Y" shape anymore, the bottom of the Y being a screw thread no 10 and the top goes into the bed joint .... real handy, used to be able to buy them by the box, simply drill with a 10mm, plug and screw!

Title: Re: How to tie in a wall
Post by Windy Miller on Jan 3^rd, 2005, 11:18pm

Allo Robbo! ;D

Was waiting for you to say summat!

Windy

Title: Re: How to tie in a wall
Post by Chaddy on Jan 3^rd, 2005, 11:24pm

Robbo this is the screwfix number of the tie i mentioned previously 31633.

Not y shaped but would do the same job.

Title: Re: How to tie in a wall
Post by big_all on Jan 3^rd, 2005, 11:31pm

wrote on Jan 3^rd, 2005, 10:52pm:

aaahhh got ya ::) ::) ;D ;)
just like to practice post and paste or was it paste and post as several people took ages telling me how to do it and i dont want to forget how to do it ;D ;D ;D ;D ;)

Title: Re: How to tie in a wall
Post by Chaddy on Jan 3^rd, 2005, 11:35pm

Nice one m8 ;D ;D ;D

Title: Re: How to tie in a wall
Post by JerryD on Jan 4^th, 2005, 12:03am

with a 4" cavity you'll need a longer than standard tie. I would use these:

Screw it to the existing wall as you build up the new blockwork so that they fit into the bed joints of the new wall.

Most merchants list these as "frame cramps" but they're ideal for what you want. :) They come in various lengths.

Title: Re: How to tie in a wall
Post by JerryD on Jan 4^th, 2005, 12:10am

Regarding the floor thickness, have you ever tried breaking up a 4" thick concrete floor! A partition wall like that will be no problem for a 4" slab, remember this was a garage with a 1.5 tonne car sat on it, possibly with 4 people in it.

As long as the concrete was 'good stuff' when it was laid and not some crappy weak flakey diy soup you should be ok. (don't mean to be rude about diy concrete but I have noticed some like to make it really wet so it 'self levels' ::))

Title: Re: How to tie in a wall
Post by diydooer on Jan 4^th, 2005, 8:12am

Hi

Thanx everyone for your help and suggestions.

Jerry D, I mentioned the fact about the 1½ tonne car to the original building designer and he didnt seem too convinced but the wall no doubt weighs considerably less. I do realise I wont be able to build upwards any higher to create a second floor without having to dig new footings etc.

Chaddy, SFX 31633 would appear to be the correct item I am looking for as long as they will be long enough. SFX dont state the length. I will email them.

Title: Re: How to tie in a wall
Post by JohnDavies on Jan 20^th, 2005, 5:10pm

Not too convinced about the car arguement - a car's weight is spread over a wide area, courtesy of four 'footprints' one on each tyre.

I would talk to a structural engineer.

John D

Title: Re: How to tie in a wall
Post by JerryD on Jan 20^th, 2005, 5:46pm

Actually a cars weight is concentrated into 4 very small areas. An average car with 4 people in it weighs about half a tonne at each tyre. The tyre footprint is about 0.015 sq metres which equates to a load of about 3.33 tonnes per sq metre

This particular wall weighs about 900kgs over a footprint of 0.27 sq m. This also equates to a load of about 3.33 tonnes per sq metre.

I agree about getting professional advice but it's not as if you're trying to build something weighing 10 tonnes.

We built some offices in a garage workshop a while back, the unit was a typical modern industrial unit with a concrete floor. They wanted a two storey office built straight off this floor, to create a reception, cloakrooms, mot waiting bay etc with their own offices above. The engineer asked for a test hole to be broken through the concrete slab, This showed the floor to be 150mm thick concrete.

This was approved for the two storey build. In addition to which they serviced and repaired commercial vehicles, there were readymix lorries, skip lorries etc all jammed in there. The total load on that floor was enormous.

However, it was very good concrete.