Renovating (painting) old sash windows myself - advice needed

[Sorehipsamiperi]

We have original sash windows under layers and layers of old peeling paint. I've been let down by a local painter and have set myself a challenge to tackle them myself before the weather gets too cold.

I need to remove the paint (seems to be doing that all by itself to be honest) but the main problem is where the paint and old putty has pulled away at the sandstone. My research so far indicates I need to remove paint (without a heat gun apparently 😭) and then fill in the holes/gaps and deteriorated sandstone with burnt sand mastic before repainting.

Has anyone tried doing this? Can anyone offer advice? Is this foolish for a novice diy-er to attempt?

We can't afford full renovation of the windows for a number of years (and can't have uPVC due to conversation area). So my aim is to make them watertight and improve the appearance in the short - medium term.

I would not overthink this and just dive in with a sander to begin taking the layers of paint off. You will know better what to do as you proceed.
You are very lucky because seeing the shape those windows are in you will have a hard time making it worse!
Good luck.

I did mine this summer. Not quite as bad as yours but nearly.

Sand to remove peeling paint.
Use a palette knife to scrape off broken putty.
Replace putty and fill holes in the wood.
Sand wood again.
Prime and paint.

Just don’t rush. It takes time, but it’s perfectly doable.

Why without a heat gun? Possibility of lead paint? Just use a good mask. It's outdoors so there's plenty of natural ventilation.

I think because the old single glazing could crack? But happy to be told otherwise!

Takes ages! Scrape off the paint then sand everything smooth.
Any areas of rot should be scraped/pared out, paint on "wet rot repair" liquid (I think Ronseal do one?) Then use two-part wood filler. Sand it smooth, take.your time to get a good finish on that bit! Hopefully you'll not have too much rotten wood. I find it's the cills that go first, which can be replaced by a joiner.
Putty in the crevice between frame and glass.
Overlap the paint onto the window glass itself by a couple mm - use good quality masking tape for that bit.

None of it is difficult but it takes ages. Or, it took me ages, at least!

There is some good advice about sash window repair over on https://www.periodproperty.co.uk/forum/forums/period-property-discussion-forum.1/

Thanks everyone, I feel like I can do this! Amazingly the wood is good and no signs of rot. My main concern is where the mastic is degrading but I've found some YouTube videos and think I can patch it up. Thanks for the tips and confidence building!!

@Sorehipsamiperi you could certainly do the frame with a hot air gun.

Budget permitting, I'd seriously think about getting new sliding units made up with double glazing. I renovated our sash window 20 years ago like you are doing but decided to get it double glazed 6 years ago when we could afford to. Makes such a difference. It cost £650.

It is hard fiddly work and however thorough I am it all needs doing again every two years! Ours get the sun on them and that does not help. Yours look bigger than ours but is it possible to lift them out and work on them inside? You then get access to all areas for window and surround. Not the best time of year to be doing them though (mind you whenever is). Good luck.

The windows are huge and we have three bays, so making up new ones would cost c.£35k. The council approved uPVC ones £20k. We'll likely need to at some point but can't afford to just yet!

No it should have been done over the summer but I was let down by someone I'd waited months for. I might aim to do the worst ones now and leave the rest until spring.

You can use a heat gun, but no where near the glass as it will crack.

Sand, scrape and fill, sand and use out door all weather paint. Takes a while. But very satisfying when finished.

Sorry to jump on this as we are currently in a very similar situation!

Can I ask how your managed to paint the windows without them sticking / allowing the sash still to slide? We haven’t started yet, but a lot of the professional advice I’ve seen online says to take the units out which is wayyy beyond my ability 😂

also, is there a specific putty that you used? I think we have everything else that we need.

thank you

Yes it does!
I managed to crack about three small panes before I realisedtot was the heat gun.

I would save up for the upvc ones, we had the original sashes in the first house we had ……they were crap. Draughty,cold , noisy easy to break into. If the victorians had had upvc/aluminium you can bet they would have used it.

Its the 21st century and people are still living behind a couple of millimetres of sinle glass 🥶.

Read up on the dangers of old lead paint.
Stripper may be the safest way

Hi again, taking them out completely is not difficult once you have done one/ learnt the technique and if they are not big windows. Take the beading off (prob the worst bit). Pull lower sash out and disconnect the weights - do not forget to tie a knot in the rope so that it does not disappear inside the frame. Top window same principle. I would guess you could find this process online. Hope it helps. Obvs you have no protection from the elements during the process unless you erect/stick up a screen/board type thing

I didn't take mine out. If you do thin layers of paint and slide them up and down a couple times as they dry that seems to work!

And linseed oil putty - kneed a little bit as rhe warmth of your fingers makes it softer and smoother.

Out windows are from 1802, you can see the mouth marks, ripples, etc, so I dont want to rip them out for upvc. I have secondary glazing and wool interlined curtains though... if I didn't like character houses I'd definitely replace with modern wood dbl glazing!