How to install uPVC windows in timber frame clad wall

[Ben100]

Hi,

 

I'm about to install uPVC sash windows into my new timber frame extension. From watching this guy, my understanding is the process goes something like this.

 

1. Breathable membrane to be stapled over sheathing and into window opening
2. Flashing tape to be installed at the bottom of the window and overlapped to the external wall
3. Window to be placed in the opening and levelled with shims
4. Once level screw in place and mastic around external and internal gaps

 

 

 

 

The issue I have is where does the window sit in the opening? Does it sit flush to the timber frame sheathing and the cladding buts around the window in some way? Or does the window protrude from the timber frame sheathing and the cladding guts up to the window? I've also seen some installers use timber seals and battens on the outside so the window can sit back in the opening.

 

This is how I believe it should be installed, but I'm not certain.

 

 

I'm a bit lots down the rabbit hole of YouTube videos on this one and would appreciate any advice

 

Here is one of the windows.

 

 

[tonyshouse]

I like windows set well back inside the wall 

[Big Jimbo]

..You have only got stub cills on those windows. A couple of things.Is your outside cladding going on timber battens....................sent you a p.m.

[Gone West]

Ideally the windows would be set back into the wall behind or in line with the insulation.

 

[Big Jimbo]

2 minutes ago, PeterStarck said:

Ideally the windows would be set back into the wall behind or in line with the insulation.

 

Or atleast in line with the insulation Peter. Is that your place ? If it is your cladding is still looking fantastic. I wish i had the bottle to build using I-beams. As it looks like i might sell on, i still concerned that so many mortgage lenders consider it "Non standard construction" I wish they would move on. Brick and block is so out of date.

[Gone West]

Just now, Big Jimbo said:

Is that your place ?

No, it's just a picture I've got showing open cladding.

[Carrerahill]

1 hour ago, Ben100 said:

Hi,

 

I'm about to install uPVC sash windows into my new timber frame extension. From watching this guy, my understanding is the process goes something like this.

 

1. Breathable membrane to be stapled over sheathing and into window opening
2. Flashing tape to be installed at the bottom of the window and overlapped to the external wall
3. Window to be placed in the opening and levelled with shims
4. Once level screw in place and mastic around external and internal gaps

 

 

 

 

The issue I have is where does the window sit in the opening? Does it sit flush to the timber frame sheathing and the cladding buts around the window in some way? Or does the window protrude from the timber frame sheathing and the cladding guts up to the window? I've also seen some installers use timber seals and battens on the outside so the window can sit back in the opening.

 

This is how I believe it should be installed, but I'm not certain.

 

 

I'm a bit lots down the rabbit hole of YouTube videos on this one and would appreciate any advice

 

Here is one of the windows.

 

 

Onto our timber frame we had 50mm x 50mm treated timber firestops, we brought the windows out flush with these, we had a block outer skin so the block came up to the front face and then render right up to the uPVC.