Materials for window recess

[tlundberg]

Time to build some window sills. The sills are quite deep, 31 - 32 cm, so there's nothing ready-made to buy, so I have to build my own. I'm thinking of using MDF on the sides and top, but I'm wondering what to use at the bottom. I'm worried that the MDF will swell and look bad if/when water gets on it. For example, if you miss wiping up any spills while watering the plants. Or if you have a flowerpot that leaks a little.

Previously, I've built with planed wood, but then the sills weren't as deep. Now I can't find anything wide enough.

Another option is to cut up a shelf in some glued wood type. But I don't like it if you can see through the paint that it's glued. I think it looks a bit odd in a window.

The sills will be painted white all around.

What suggestions do you have?

 

[mrcap]

Boards of this type that are painted correctly? Available in different widths.
https://www.hornbach.se/shop/Limfog.../artikel-detaljer.html?varCat=S16717#v1063112

 

[Patrik Hazard]

I also think that glue-laminated wood where the staves are full length should turn out quite well. Otherwise, you could glue together two floorboards or similar to just have a joint. Or maybe plywood of higher quality?

 

[xibeca]

I have used a lot of knot-free whole stave glue panels from www.primpanel.se
Most of it painted with linoljefärg with good results.

 

[Freka]

Time to build some window sills. The sills are quite deep, 31 - 32 cm, so there's nothing ready-made to buy, so I have to build my own. I'm thinking of using MDF on the sides and top, but I'm wondering what to use at the bottom. I'm afraid the MDF will swell and become unsightly if/when water gets on it. For example, if you miss wiping up a spill when watering plants. Or if you have a plant pot that leaks a little.

Previously, I've built with planed wood, but those weren't as deep sills. Now I can't find anything that's wide enough.

Another option is to cut up a shelf in some laminated wood. But I don't like it if you can see through the paint that it's laminated. I think it looks a bit strange in a window.

The sills will be painted white all around.

What suggestions do you have?

Use MDF for the windowsill as well; I've also made my own window sills and shelves for all my windows.
I used 12mm for the sill on the sides and top, and a board with 22mm thickness. Then I painted them with oil-based hard paint. This prevents pots, etc. from getting paint scratches or pots from "sticking" to the windowsill with the paint coming off under the pot.

 

[tlundberg]

Wood boards of this type that are painted the right way? Available in different widths.
[link]

I like that one! Unfortunately, I don't have a Hornbach nearby, but I'll see what I can find around here

 

[tlundberg]

I also think that laminated boards where the strips are full-length should turn out quite well.

I didn't know there were full-length strips. That does look much better

Otherwise, you could glue together two floor planks or something similar to have just one seam.

That could be an option! You can fill the seam, so it should be very discreet

Or maybe plywood of higher quality?

I've also considered that. I searched around a bit, but only found people advising against it.

 

[tlundberg]

I have used a lot of knot-free full stave glue panels from www.primpanel.se
Mostly painted with linoljefärg with good results.

Have you bought directly from them, or do you have a retailer nearby? Price?

 

[tlundberg]

Use MDF for the windowsill as well, [...] Used 12mm for the sides and top reveal, board in 22mm thickness.

I read somewhere that you should have at least 19mm thick MDF to prevent warping. How long have you had your reveals? How have they held up?

Then this was painted with oil-based hard paint. This prevents pots, etc., from causing paint scratches or pots from "sticking" to the windowsill, pulling paint with them.

Glad you mentioned the scratches - I hadn't even thought of that! Do you remember what the paint you used is called? Is it also waterproof enough to protect the MDF from overflowed saucers, etc.?

 

[Freka]

Read somewhere that you should use at least 19mm thick MDF to prevent warping. How long have you had your smygar? How have they held up?

Good that you mentioned the scuffing - I hadn't even thought about that! Do you remember what the paint you used is called? Does it also become waterproof enough to protect the MDF from flooded plant saucers, etc.?

It becomes sealed, if anything happens you would have to spill a lot. Make sure to sand the surface first so the paint adheres and apply 2-3 coats. Ask for oil-based paint with hardness and tell them what you'll use it for, I can't remember which brand I used.

 

[Freka]

My soffits and windowsills I made 13 years ago are just as nice now as they were then. MDF is a stable material and does not change shape. Very pleasant material to work with.

 

[Johan456]

MDF, painted with carpentry paint works excellently. There are pots on it and spills occur, yet no marks. Well, after x years you might need to touch it up, but the MDF is not damaged. Mine are painted with Alcro, V-Mill, semi-gloss.