A question about fitting sash windows

[Otto]

So hypothetically speaking, if one were to remake and replace some completely rotten, 40 year old timber sash windows - in their own private dwelling, would the window frames need to be painted on the outside where they sit into the opening?, do they need to be painted at all? Would bitumen paint be better? Would Flashing tape be better still? or should they be wrapped in blue plastic?
many thanks

 

[Jacob]

So hypothetically speaking, if one were to remake and replace some completely rotten, 40 year old timber sash windows - in their own private dwelling, would the window frames need to be painted on the outside where they sit into the opening?, do they need to be painted at all? Would bitumen paint be better? Would Flashing tape be better still? or should they be wrapped in blue plastic?
many thanks

There is no alternative to paint - or varnish which amounts to the same thing.
I've been using Linseed oil paint for about 15 years now, on trad doors and windows and wouldn't use anything else for exterior work. It's not cheap by the tin but it is very economical in use. I've only used the one brand so far "Allback" but there are others as it is catching on fast.

PS or do you just mean the bits behind the masonry? in which case no. Old sash box frames were never painted where out of sight, always painted after installation. it allows them to "breathe" i.e. dry out if they get damp, in winter etc.

 

[Otto]

Hi Jacob, thanks for replying, I do mean the top, sides and bottom of the sill that are out of sight.... I made a lot of furniture before but this is my first attempt at windows so it's all very new to me. So I can just leave the outside of the frame treated with preserver? No paint? The windows themselves use spiral balances so do not have a box frame, just 33mm jambs

 

[Jacob]

Hi Jacob, thanks for replying, I do mean the top, sides and bottom of the sill that are out of sight.... I made a lot of furniture before but this is my first attempt at windows so it's all very new to me. So I can just leave the outside of the frame treated with preserver? No paint? The windows themselves use spiral balances so do not have a box frame, just 33mm jambs

In that case I don't know. Modern joinery is very different. But if detailed correctly it should not need preservatives in the first place.

 

[Ollie78]

Just paint, all that other stuff is not required. Personally I like to paint everything before final assembly / installation.

Ollie

 

[Jacob]

Just paint, all that other stuff is not required. Personally I like to paint everything before final assembly / installation.

Ollie

The basic paint problem is that it if it keeps water out it can also keep water in. Hence the rotten timber sometimes found under what looks like a good painted surface. In fact I've cut through cills which were water logged.
So I never bothered to paint where it was not necessary to keep rain or condensation off, and I don't they did either in the good old days.

 

[Phil Pascoe]

I suspect they weren't painted on unseen parts more to save time and money than any other reason.