How to attached studwall with cavity with no ceiling connection

[Bruce]

We are currenly insulating and external wall with a timberframe and a cavity to the studwall, the goal is to not to attach the fram to the brick att all if possible. The crux is that the wall is under a window and then it ends at a door so no ceiling nor no side connection.

 

Does anyone have an idea on how to build this without making it super wobly? I guess we need to attach it somehow to the wall but I'm not sure how to do that and make it BC compliant. To the left and above the window we have steel that we can potentiall connect to. Is there any spacers that can do the job or can the window board just do it all? Though that doesn't stop the wall from movin away from the brick wall. 

 

[ProDave]

Why don't you want to attach it to the wall?

[Bruce]

7 minutes ago, ProDave said:

Why don't you want to attach it to the wall?

To avoid leading any pentrating water/moisture that comes through the brick to the timber frame as per BCO demands.    

[Big Jimbo]

If you put a bit of DPC behind the bracket, and a squirt oif silicon in the screw hole, how is any water going to get to the timber frame ?

[Bruce]

11 minutes ago, Big Jimbo said:

If you put a bit of DPC behind the bracket, and a squirt oif silicon in the screw hole, how is any water going to get to the timber frame ?

That souunds like a good sollution. I was somehow fixated on using a timber batten as a bracket which aboviusly they where not happy with. Your sollution with a steel bracket I didn't even think of.

[Bruce]

On 03/02/2026 at 13:18, Big Jimbo said:

If you put a bit of DPC behind the bracket, and a squirt oif silicon in the screw hole, how is any water going to get to the timber frame ?

BCO have clairfied that they expect any wall ties to have sufficient slope towards the external wall or have a drip in them. We intend to use the below type combined with DPC which hopefully gets their approval.

 

[Oz07]

Stainless steel?

[Nickfromwales]

18 hours ago, Bruce said:

BCO have clairfied that they expect any wall ties to have sufficient slope towards the external wall or have a drip in them. We intend to use the below type combined with DPC which hopefully gets their approval.

 

Don’t use those, they’re massive cold bridges. 
 

https://www.travisperkins.co.uk/wall-and-frame-ties/ancon-staifix-stf6-timber-frame-cavity-wall-tie-box-100/p/252293?srsltid=AfmBOoofEZbj_x_ZnYybhpBGqkrwLBomudNsJ_VFHDfzfUP3PiK7j8et_Zk

[Roundtuit]

1 hour ago, Nickfromwales said:

Don’t use those, they’re massive cold bridges. 
 

https://www.travisperkins.co.uk/wall-and-frame-ties/ancon-staifix-stf6-timber-frame-cavity-wall-tie-box-100/p/252293?srsltid=AfmBOoofEZbj_x_ZnYybhpBGqkrwLBomudNsJ_VFHDfzfUP3PiK7j8et_Zk

They're for tying a brick skin to a timber frame during construction, so not really suited to your application IMO.  You'll need to return the stud wall to the brick wall (where you have circled blue) to close the cavity, so use a strip of  dpm between the timber and brickwork.  That should stiffen your stud wall up enough to use maybe one intermediate bracket, and finish off by using the window board fixed to both inner and outer skin.

[Bruce]

On 04/02/2026 at 18:45, Oz07 said:

Stainless steel?

Sorry but I don't understand the question? Are you telling me it has to be SS?

 

10 hours ago, Nickfromwales said:

Don’t use those, they’re massive cold bridges. 
 

https://www.travisperkins.co.uk/wall-and-frame-ties/ancon-staifix-stf6-timber-frame-cavity-wall-tie-box-100/p/252293?srsltid=AfmBOoofEZbj_x_ZnYybhpBGqkrwLBomudNsJ_VFHDfzfUP3PiK7j8et_Zk

The reason I have looked at the one pictured was that I don't see how to use those ties when the brick wall is already in place. But maybe they can be bent and drilled out to work?

 

 

8 hours ago, Roundtuit said:

They're for tying a brick skin to a timber frame during construction, so not really suited to your application IMO.  You'll need to return the stud wall to the brick wall (where you have circled blue) to close the cavity, so use a strip of  dpm between the timber and brickwork.  That should stiffen your stud wall up enough to use maybe one intermediate bracket, and finish off by using the window board fixed to both inner and outer skin.

BCO didn't seem to like the idea of any timber touching the external wall (on the "external" side of the VCL), but yea it looks like the window board is going to have to be part of the stud wall structure/fixture.

[Roundtuit]

1 hour ago, Bruce said:

BCO didn't seem to like the idea of any timber touching the external wall (on the "external" side of the VCL), but yea it looks like the window board is going to have to be part of the stud wall structure/fixture.

Has the BCO not indicated what would be acceptable? Maybe have a look at metal galvanised stud systems?  Might be a bit more expensive, but for a small area wouldn't break the bank.

[Bruce]

On 05/02/2026 at 21:50, Roundtuit said:

Has the BCO not indicated what would be acceptable? Maybe have a look at metal galvanised stud systems?  Might be a bit more expensive, but for a small area wouldn't break the bank.

They are quite assertive that they cannot give tips/tricks or recommend anything really, just confirm or deny design suggestions due to liability reasons. I really think that with a bit of dpc and those sloped brackets that they will be happy so we are goign with that for now.