Fitting windows into a shiplap wall

[Guineafowl21]

Here’s a pic from when I first moved some machines in, to give an idea:


The inner lining is 11mm OSB, then 95x45mm studs, then 15x137mm shiplap. I’m quite happy making some simple swinging windows in a frame, but not sure how to do the opening correctly, so that water doesn’t cause problems.



In the drawing, existing studs are in black, new framing in green. The lintel (not labelled) should be thicker for a load-bearing wall, I assume. Not all the walls are. As far as I know, the sill (or cill?) should protrude beyond the shiplap outer layer, have an angled top and a drip groove underneath.

Should the casing be flush with the shiplap on the outside, and studs on the inside?
Should the sill protrude beyond the studs on the inside?

Any advice appreciated.

Many thanks.

 

[Trevanion]

I personally would fit the windows sat just behind the ship lap with the ship lap overlapping around the perimeter of the frame, and the cill extension protruding out beyond the ship lap.

 

[duke]

Can you provide an exterior pic?
Often I flush the window with the outside surface, make your sill then run the trim onto the sill. Caulk it well then paint, if staining not painting caulk after with a matching colour or clear/translucent caulk.

 

[Guineafowl21]

The best I can do is another pic just after the machines were moved in. You can see the green shiplap through the ‘horse windows’.



Thanks for the advice. I’ll do a drawing to confirm.

 

[Guineafowl21]

Something like this?

 

[duke]

This what I meant.

 

[Guineafowl21]

This what I meant.View attachment 33510

I’d have to cut the opening to avoid the wrong part of the shiplap, leaving a gap under the trim?

That should be ok, as I can custom-size the windows, although I’ve already got the glass, which I think is greenhouse glass.

 

[duke]

So you are going to make the windows first frame and all then you will know your rough opening so you can do your layout on the exterior surface?

 

[Guineafowl21]

So you are going to make the windows first frame and all then you will know your rough opening so you can do your layout on the exterior surface?

Yes, if that’s best. I’ll just have to size the frame to fit between the flat areas of shiplap.

 

[duke]

Maybe there is a thread already on this forum that covers this type of window construction. I'm sure Mike G can help.

 

[Cabinetman]

Thank you all, this is of particular interest to me as I am fitting windows into a board and batten wall on my new workshop in a couple of months. Complicated by reusing an old sash window for decoration on the outside and a D/G panel on the inside, also the wall will be quite thick as it’s made from 2x4 with 1” planks on the outside and 3” of continuous PIR insulation on the inside then 1” furring strips with Drywall, a total of about 10”. ( crikey I hadn’t added it up till just now, but it won’t be impinging on work space so no problem lol)