Just thinking about specifying the timber reveal depths for Aluminium windows. Downstairs, I have brick veneer - 250mm thick. Upstairs, I have XPS rendered cladding - 200mm thick. Just wondering what the theory is behind specifying window reveal depth? Here are some thoughts/questions:
1. Are windows attached to be flush with the outside edge of the reveal?
2. Say the reveal is 130mm, and is narrower than the 250mm thick wall. Is the reveal lined up with the interior face of the wall? Then, the external 120mm of the wall is not covered by the reveal. What is done to finish this exposed 120mm? I guess the lower edge has the brick sill sloping down for drainage. Are the sides and top just exposed material?
3. Is it most energy efficient to have the window aligned in the centre of the wall thickness - i.e. in a 250mm wall, the centre of the window is 125mm from the inside, and 125mm from the outside.
4. Do you prefer painted or unpainted reveals? Are there any problems with unpainted reveals - I like the look of timber, so I prefer to see the timber grain, and am happy to lacquer them, but only on the inside, not the outside! Anyone have any experience with unpainted reveals?
5. Will the reveals be exposed to the elements, or are they sealed and protected by the aluminium window edge. Maintenance issues with painted vs unpainted timber reveals?
The way I'm thinking, it is best to have the windows mid-depth in the wall, and the windows are aligned to the external edge of the reveal, so... ideally, the reveal depth should be half the thickness of your wall.
Thanks in advance for the advice.