Child Item

How to install new window in weatherboard house?

Hey there, am looking at replacing a timber fixed window in my weatherboard house.

It seems that all off-the-shelf timber windows these days are built for brick veneer houses?

e.g. New window is 138mm deep (without wind moulds).

If we factor in plasterboard (10mm) + stud (90mm) + weatherboard (25mm) = 125mm

So window frame will sit 13mm proud of weatherboards.

Is this common/how is this usually dealt with? Scribers on the sides? How do exterior architraves work in this situation?

Am I also correct in thinking that the metal flashing I buy for the window head flashing will need a horizontal leg of around 15mm to cater for the window? Or would we go 20mm or more?

Thanks for your help!

Find more posts tagged with

Tools and Materials

Building and Construction

Doors and Windows

Comments

EricL

Hello @samh25

Thanks for sharing your question about windows. I'm aware that the scribers are placed on the side of the windows and that the exterior architrave are used to finish the look. In regards to weather protection having a larger flashing (20mm) would provide better coverage.

Let me call on our experienced members @Nailbag and @Dave-1 for their recommendations in regards to window installations.

If you have any other questions we can help with, please let us know.

Eric

Nailbag

Hi @samh25

Your have two neater options in dealing with the sizing issue of the window reveal (frame).

1. Buy custom (very expensive).

2. Mark and cut the excess off with a saw.

The 2nd option I have done several times, especially during a COVID reno when I had to take what I could get for materials. I used a circular saw fitted with a guide fence on a min depth setting to pass through the frame thickness and had it very well secured. You could also use a Jigsaw which is a safer option for the less experienced. And of course a short sharp hand-saw. Just flip the window for each side,

Below is a diagram to explain. your flashing installation.

Nailbag

Screenshot 2025-04-21 at 7.44.41 am.png

Screenshot 2025-04-21 at 7.46.54 am.png

Dave-1

https://www.workshop.bunnings.com.au/discussion/comment/51349#Comment_51349

Afternoon @samh25

I have never done a window replacement before (One day I hope 🙂 ) Tho @Nailbag example certainly sounds like the way forward. It makes it a lot easier when yopu know somneone has been there, done that before .

Dave

samh25

https://www.workshop.bunnings.com.au/discussion/comment/51349#Comment_51349

Thanks mate - this is really helpful. Appreciate your help.

Child Item