Painting sash window nightmare

[IOW]

Hi, I’m new hear and just need your advice. I’ve just had all my Victorian villa sash window renovated sanded and now painted to a great expense in the Isle of Wight. In 4/5 months the paint has bubbled and cracked and not adhered to the wood. Mainly on the bottom of the sashes and the sills. For your information the painter did not strip the old paint off just sanded. I’ve had the painter back with his so called specialist friend and has told me the wood has no juice left in it and is dead. That’s why the paint he used (He says the best Weathershield 12 and 3 ) is not adhering to the wood. He also tells me that the old sashes at one point had been varnished so once again it makes painting old sashes hard because the varnish is in the grain. His out come would be to replace all the 32 windows. I was like that is not an option and need another opinion. That is why I’m turning to you guys for some well needed help. Is there a specialist product out there that I can use to paint the window with that will actually work on 100 year old windows. Just to also confirm that the Weathershield did work on the new replacement wood and sashes so I do see his point, but there must be a way to save my windows and paint the 100year old wood. Thank you in advance to professional advice.

 

[malcolm]

We're not professionals on here but looks like the wood is wet and is popping the paint off to try to find a way to breathe and dry out. Those cracks will let water in but won't let it out again and the wood will be dust in a few years.

Modern waterproof finishes are terrible for wood. In the olden days they used linseed paint and windows would last for hundreds of years. These days wooden windows don't last for more than a few years because of the modern paints so people replace them with UPVC.

Strip all the modern paint off with a heat gun to get back to wood and paint it with linseed paint. That will allow the wood to dry out so it doesn't rot.

 

[stuart45]

I've got mostly timber single glazed windows, and a few of them have had issues like that. I do all the work on them myself, or it would probably not be cost effective to keep them. I've replaced a couple of cills, and some glazing bars, but using wood hardener has helped in other places.

 

[Gothichome]

IOW, welcome. My solution would be to sand back down to as close to bare wood as you can. Mixup a 50/50 solution of a good boiled linseed oil and turpentine. Paint on the mix, don‘t be stingy with it, let it soak in as much as it will take. Let dry for a few days or until the surface is dry, meaning no tackiness. Another light sanding to provide some bite then repaint. The turps will act as a carrier for the linseed and draw it just under the surface and as a drier for the mix.
Ron

 

[Gothichome]

Oh, and find another painter.

 

[eezageeza]

Follow all the advice re linseed paint, and you wont go far wrong. I think its important to sand back to bare wood as fully as you can, and you'll need patience and perseverance to get there (DAMHIKT - but I am doing similar work on 22 sash windows here!).

If you're considering doing the work yourself, and if the budget will allow, have a look at the Festool Rotex 90 sander to help in this. As with all Festool gear it's horrifically expensive, but IMHO actually worth it for this job. I've found it takes hours off the prep time.

 

[Cubist]

specialist friend and has told me the wood has no juice left in it and is dead.

Clearly that 'specialist friend' was. a graduate of the morons school for old pals! Con artists!

Lots of good advice from others here and all of it worth following but would modify Gothichomes last comment to add - "and sue the beggars after reporting them to trading standards'.

 

[IOW]

Thank you all so much. So what your saying is the Weathershield is totally the wrong paint and is for new wood hence why it adhered to it. You hire professionals for a reason. It’s a right mess then. Not sure what to say to him now as he’s not going to want to do it all again. The scaffolding cost 5k.

 

[stuart45]

Tell him you aren't happy with the work. A pro painter should prep a surface properly before painting. If the timber is beyond repair, they should discuss the problem with you, rather than just painting over it. If it's only the cill and bottom rail, it should be repairable without window replacement. It's hard to see how bad the timber is without burning the paint off.

 

[mardinor]

Sorry, but that painter is not a professional. As Stuart says above, this is bog standard work they do day-in and day-out and he should have specified to prepare the wood properly. To fail in such a short period suggests a major error, not purely poor preparation. And a reaction with the previous coating is unlikely to happen only in these locations. My money is on the wood being wet when he painted it, and that moisture is now trying to get out. That explains where the failure has happened.

No pro would specify solvent-based gloss these days. The best paints are now water-based. And pros also tend to steer clear of Dulux. And he would know that 100-year old wood is far superior to any softwood you can buy new these days, and the 'wood has no juice' line is total nonsense.

You should ask him to put the work right, or take him to small claims court.

I renovated and painted all my sash windows 20 years ago. The windows date from 1890 and are better-than-new. You need to sand them back to bare wood and apply a modern water-based paint system from a brand you've probably never heard of. I've used Jotun Demidekk and Bedec and both come with 12-15 year maintenance cycles. After 20 years it's time now to repaint the south-facing windows. They have cracked and peeled in the lower areas, but look OK. And more importantly, don't form a film like that Dulux has done, that causes trapped water and rot. I've tried linseed oil paints but they take days to dry, so are tricky with windows in-situ, MUST be used on bare wood only, and the horizontal surfaces tend to get mouldy. They sound great in principle, but in practice modern paints have improved immensely in the last decade or so.

If I were in your shoes, and being practical, I would do 3 things:
1) Get the painter to rectify or sue. Seriously.
2) Sand back to bare wood just the cills and lower 6 inches of the bottom sash where the paint has failed and reapply the Dulux system, when the wood has dried. Get the painter to do it (watch, make sure they sand fully and check moisture content with a probe) or another one (specify the work properly, then reclaim the fee from painter 1)
3) When the windows next need doing, strip them back fully to bare and do it properly as suggested above

Sorry you've learnt a lesson we all do with period properties: 90% of the time a tradesman will not understand them and you have to do the work yourself.

 

[malcolm]

It's very mainstream to paint wood in waterproof coatings to keep the water out. Water always gets in after a while when cracks appear but it can't get out because the coating is waterproof.. The same will happen to the new windows over time for the same reason. It's got nothing to do with how old the wood is. It will be water trapped in the wood pushing the new paint off.

What's needed is a strip back to wood and repaint in a breathable finish that will let water out. I use linseed and is great for breathability but mardinor makes a good point there are other paints like Bedec that are breathable (and probably keep a nice finish for longer than linseed which tends to go matt and attracts dirt). It's also a good point to see what the wood looks like once the paint has been stripped off. Worth searching the forum for discussions about paint.

You do want to be using a specialist paint on exterior wood. The mainstream ones are usually waterproof. Painters are happy to follow the mainstream because it means they can come back every 5 years and paint again. With linseed that is not necessary and there is almost no prep required before another coat to make it prettier of change the colour (don't know about Bedec as I haven't used it). If you can cope with doing it DIY that's normally the best way to get things done properly. A scaffold tower should be cheaper than scafffolding at around £1000 and will come in useful for other things. Mine is in the living room at the moment ready for painting the ceiling.

 

[Feltwell]

"the wood has no juice left in it and is dead"

Yes, funnily enough once you chop a tree down and make it into a window, it's dead. Add 100 years on and it doesn't come back to life! As for "juice"....the painter is talking utter rubbish.

All good advice above, personally I would avoid Dulux like the plague. Strip at least the bad areas back to bare wood and use a microporous water based paint, Bedec MSP being my favourite. Moisture won't get trapped behind that.

Linseed paint - undoubtedly good for wood, but my personal experience is that it's not very durable and goes dirty too easily, on horizontal surfaces especially. I switched to Bedec MSP which is both infinitely easier to use and seems to be much more durable.

 

[malcolm]

Linseed paint - undoubtedly good for wood, but my personal experience is that it's not very durable and goes dirty too easily, on horizontal surfaces especially. I switched to Bedec MSP which is both infinitely easier to use and seems to be much more durable.

What do you need to do to Bedec when you want to repaint? I guess if it's breathable it won't have cracked so you can leave it on maybe sand it a little and paint straight over it. I was drawn to linseed after having to spend 2 days stripping my huge bay window back to wood a second time in 5 years. I realised modern paints are a poor choice. I've never tried Bedec but it would be useful to know.

 

[IOW]

Ok I feel I’m getting somewhere. Just a couple more questions.

So from what your saying the key is that the painter hasn’t sanded/stripped down enough and left old paint on that doesn’t let the wood breath. Hence the water trying to escape when the new paint is on. So with this in mind, that’s why you say we need it to go to bare wood.

1- So my question is why do I have to use bedec/ specialist paints on old sash windows? Is the wood different? Is it because of the age of the wood and how they have been treated prior. Sorry for my ignorance I just need the whole story before I go back to this idiot.

2- They said they wanted scaffolding prior which was more secure for them to paint. . How high can a scaffolding tower go to feel comfortable and secure. My windows are on the second floor.

3- Painter told be they can’t burn off the paint useing a heat gun because his insurance won’t cover it in case he burns the house down. Is this true in 2023 ?

 

[TudorCottage]

1. Bedec and some other brands are breathable/microporous paints. Your Sash windows are like any wood, if it gets wet it needs to dry or it will rot. Bedec will let air pass through the paint allowing the wood to dry, Dulux will not.

2. I have a scaffold tower which reaches the apex of my roof (2 story’s) and I feel very secure on it. It has 4 supports/stabilisers and I wouldn’t consider using it without these in place even when I use it for relatively low heights.

3. I’m not a fan of burning paint off, but if I did I’d be worried about cracking the glass but think I’d be able to avoid burning the house down.

If it was me, I’d wait for a settled spell of dry weather and sand off as much paint as possible and leave bare for as long as possible in the dry spell to give the wood a good chance of drying out. And then paint with a microporous paint before the dry spell comes to an end. Not easy in our climate but possible if you concentrate on one window at a time.

 

[housewinnie]

I have been using this goes on nice and goes a long way..

Products | Pure Linseed Oil Paint | Ingilby Paints

Traditional solvent free linseed oil paint for a decorative and protective gloss coating on all woodwork. Pre mixed with Zinc Oxide.

www.ingilby.co.uk

 

[mardinor]

Not quite. Dulux is an old fashioned paint, so is less breathable than modern ones, but does claim to be microporous and gives a 10 year guarantee. So they will claim it’s breathable (‘microporous’), but it’s just not as good as others. About 30 years ago it was the best you could get (apart from specialist paints like linseed) but that was in the days of oil gloss.

So the problem, in much view, is not his choice of Dulux. It’s not the best, as we’ve all mentioned, and next time choose a different brand, but it should be fine on old windows for at least 5 years.

Your photos show catastrophic blistering, in selected locations. This is not the same as gradual cracking and peeling which is how you would expect the coating to fail after many years. So something has gone very wrong.

In my experience, there are two ways this could happen. It could be a reaction between the previous coating and the new coating. This is something the painter should have considered and tested, and if necessary sanded back to bare. BUT, if this were the cause I would expect similar symptoms all over, not just in the lower locations. It would also have happened within a day or so, not months later. So I don’t think this is the likely cause for those two reasons.

The other possibility is that he has applied the paint over wet wood, which has subsequently dried causing water vapour to be trapped behind the oil paint, causing blistering. Although Dulux claims breathability, this is when applied properly to dry wood. The areas where failure has occurred are those where rain settles and where paint weathers first. So these areas are most likely to have been cracked before painting and wet underneath, even if the wood appeared dry to touch. This is the only credible explanation that matches the degree of blistering, areas on the window of failure, and speed of occurrence. Looks to me like he rushed the job, not checking the wood dryness with a moisture gauge and not leaving sufficient time after sanding back for the wood beneath to dry before painting.

I’m not an expert, but neither is he. What I would expect of a professional is to apologise and promise to make good, and then for him to contact Dulux technical support to investigate the cause of the problem (though that is his problem, not yours).

I assume he offered a guarantee that the paint would last for a specific number of years? Even if not, you are entitled to expect a certain standard of workmanship and so have a legal claim, unless he specifically warned you in writing of a known issue before you agreed to proceed at your own risk.

On specific questions:
1). No, old wood is BETTER than new. It was grown slowly so has tighter growth rings and is more durable. The dryness comment is irrelevant. We’re recommending other brands only because they last twice as long and are better paints, NOT because you need a specialist paint for old wood. These are leading brands used by professional decorators. I was on a painters forum for 10 years and these were the ones they all used, never Dulux (which is for DIYers)
2) fair to ask for scaffold or tower. Few work from ladders anymore, for health and safety reasons. I would expect a pro to ask for that, even if expensive.
3) also sounds reasonable, but he should have sanded therefore.

 

[eezageeza]

One more thought.....you say 'after 4/5 months' which takes us back to mid-winter ? When it was likely cold as well as wet ?

If thats the case, then the painting was done under the worst possible conditions, and was odds-on to fail.

 

[Feltwell]

What do you need to do to Bedec when you want to repaint? I guess if it's breathable it won't have cracked so you can leave it on maybe sand it a little and paint straight over it. I was drawn to linseed after having to spend 2 days stripping my huge bay window back to wood a second time in 5 years. I realised modern paints are a poor choice. I've never tried Bedec but it would be useful to know.

If it's still sound then just a light sand and paint over it Malcolm. I'm a big fan of the stuff now, it is quite expensive but worth it I think. Promain are a good online source.

 

[marlonhambo]

I haven't been on this forum for long and only viewed a couple of threads, but I haven't seen any recommendations for Zinsser Allcoat Exterior. I painted my c1910 sash windows using it in Sep 2020 and it's looking good. Seems to be liked by decorators too, any reason it's not getting mentioned here?