Timber Windows

Hi

I'm looking at replacing current single pane wooden sash windows with new, double glazed units and want to be sure I'm making the right choice as it will obviously not be cheap and I want hear to last a long time!

The choices I have are from Company 1: European Redwood or Meranti hardwood. This company plays both of these would be 'engineered timber' and are treated using the TEKNOS system, which apparently means the frames are "dipped in primer and sprayed with very hardwearing micro-porous paint prior to being assembled which is important as it prevents cracking like you would find with a window that comes primed and then painted on site".

Company 2 will make the frames from sapele wood, but the finish would be a primed frame and probably painted on site i.e. the exact method that Company 1 suggests you should avoid!

So my question is, is it all about the wood (In which case I guess I go for sapele) or is the finishing/painting method just as important?

I should also say that there isn't a huge difference in price across all 3 wood options, so cost wouldn't be the deciding factor.

Thanks for any help!

Personally I would choose a company that factory finishes.

The teknos system if on softwood, is probably their 1410 preservative dipped, A basecoat, then 2900 top coat. Teknos paint is soft and flexible so its pretty resistant to fracturing at joints etc.

Longevity of paint finish actually drpends a lot on the joinery design to avoid water traps and critically to make sure all external edges have a 2 to 3mm round. Also the joints should be visible because the rounding continues across the jount face. That means the expansion and contraction of the rails doesnt fracture the paint line at the joint. Larger companies that have CNC machines and the best tooling will have the radiuses built into their cutters and setup.

If you can wait until spring it would be best. Why? Because all joinery paint is now waterbased and that means curing stops below 12deg. If your windows leave the factory not properly cured, then the paint wont cure fully until warmer weather arrives.

Softwood is fine if joinery is made correctly.
Im not sure there would be much benefit having meranti.

Sapele is a moderately durable, more so than softwood or meranti.

You could try georgebarnsdale -they prob have sectional drawings of their windows.

Woodspring, good evening.

Suggest you have a look at the following.

What is engineered timber? Timbmet's range of engineered timber is called TEC®. These are highly engineered solutions which provide improved stability and performance, with the look and feel of solid timber. They are made by joining/gluing multiple pieces of material together.
http://www.timbmet.com/uk/news/engineered-timber-the-facts/

https://www.trada.co.uk/wood-species/meranti-dark-red/

https://www.trada.co.uk/wood-species/sapele/

There is a load of informed reading in the above, especially durability and both timbers ability to accept painted [or otherwise finishes]

Ken.