Adding wall ties afterwards

[24sevenv24]

Hi all

I did not realise wall ties need to be in place on every course around doors. My extension consists of timber inner leaf, 50mm cavity and blockwork external. As a cheaper alternative to helical wall ties, I was considering drilling a hole in the masonry, squirting some kemfix in and inserting 150mm screws through into the the timber inner leaf. Would this be satisfactory?

Cheers

 

[noseall]

Hi all

I did not realise wall ties need to be in place on every course around doors. My extension consists of timber inner leaf, 50mm cavity and blockwork external. As a cheaper alternative to helical wall ties, I was considering drilling a hole in the masonry, squirting some kemfix in and inserting 150mm screws through into the the timber inner leaf. Would this be satisfactory?

Cheers

I’d be more worried about the slender cavity and latest reg’s.

Tie positioning will depend on the jamb closing detail, but usually every block course (225mm), yes. You can mechanically fix, yes. Be aware that BC may frown upon the cold bridge or moisture bridge (bulky cavity ties), more so than the lack of ties.

 

[24sevenv24]

I’d be more worried about the slender cavity and latest reg’s.

Tie positioning will depend on the jamb closing detail, but usually every block course (225mm), yes. You can mechanically fix, yes. Be aware that BC may frown upon the cold bridge or moisture bridge (bulky cavity ties), more so than the lack of ties.

Thanks noseall. BC approved my plans inadvance. 130mm insulation within the timber leaf and 25mm outside it. Then 50mm empty ventilated cavity.

What if Installed the screws at an angle so con
densation can run off? This should act the same as a wall tie...no?

Cheers

 

[stuart45]

How many helical ties do you need?

 

[24sevenv24]

About 7. I can only see them sold in packs of 100 and then a 50 quid tool is required for the drill. Also, can helical ties go Into timber? I figured 150mm screws and a squirt of resin would be just as good...

 

[stuart45]

They can go into timber. Never used screws myself, but it might work. When inner skins were brick the ties went in every 300mm, so you aren't too far out every 450mm. Worked on plenty of jobs years ago when the old Bricklayers only stuck them in every second block with the rest of the wall. They reckoned every block was a stupid modern idea.

 

[24sevenv24]

Thanks Stuart. Good to know. For peace of mind and to keep BC happy, I will bite the bullet and will use Helical ties. Is a pilot hole still needed in the timber?

 

[stuart45]

No pilot hole needed in the timber.

 

[^woody^]

Stainless steel screws required.