Paint Stripping Brickwork

[malcolm]

I'm struggling to remove masonry paint from brickwork. The paint is several layers deep in places. The coats underneath appear to be water based and the coat on top is probably an oil or emulsion based Dulux Weathershield type. The paint is flaking in places and comes off in a plastic layer. Other places it is stuck solid.

I've tried some samples from Stripers Paint Removers. The Kling Strip works after it has been on for several days but takes a lot of effort to remove with a jet washer which damages the face of the bricks. Their Solvistrip works best. The photo shows the first coat after about 1-2 hours having been removed with a scrubbing brush and hot water. Cold jet washer didn't touch it and the scrubbing brush seemed to smear and has left plenty of soft paint on the wall.

I'm tempted to try pressing a layer of fabric into the stripper which will hopefully peel some of the soft paint away but I don't want to reinvent the wheel if someone else can suggest what worked for them.

Anyone removed paint from bricks before? Potentially I have a whole house to do as the paint was applied before necessary repointing, and the paint failure is causing damp issues in a few places.

 

[88v8]

Plastic media blasting. Won't damage the bricks.
Not cheap, but then you can get on with life.

These people, errm forgotten where you are - edit your Profile to show your location - or someone similar nearer to you...
You may know them, they do car stuff, blasted the bonnet of my TR6 without distorting it.
http://www.blast-cleaning.co.uk/index.php?menuid=121&component=content&task=article&articleid=22

Ivor

 

[malcolm]

Tried to get a budgetary price for having the place professionally stripped by a local company but they don't seem bothered to get back to me.

Almost had success sticking a blanket to the Solvistrip. It stuck well enough to peel about 1/8th of the paint straight off the wall. Otherwise it softens the paint well but leaves a plasticy residue which doesn't dissolve in water and just smears around.

 

[Moo]

Many, many years ago, when we lived in South Norfolk, we explored the possibility of removing the paint from our lovely old house's soft red bricks.
We got in touch with (I think) Strippers of Sudbury and they came and applied test patches of two different poultices. One didn't work at all, but the other removed all the paint so successfully that you couldn't imagine that the house had ever been painted.
It was quite magical, but we just couldn't afford to have it done (it was a big house!).

 

[malcolm]

Do you remember roughly how much the quote was?

I've ordered some Peelaway 7 to see if that's any easier.

 

[Moo]

I can't remember exactly, but it was several thousand pounds, which we just didn't have at the time.
I'm sure there's a formula that would do the trick; it's just a question of finding out which one!

(Is it possible to get tester pots?)

 

[malcolm]

I've got better things to spend that sort of money on here as well. Mind you a DIY approach is maybe £15/sqm. Srippers Paint Removal offer a service where you send them a big flake of paint and they try their stuff on it to make a recommendation about what to use. Have sent them an envelope full of big flakes of paint. Something might come back from that too. Will report back if I find something effective.

 

[malcolm]

Some good progress and a new technique that might be of use to others.

Strippers Paint Removers played with the paint sample and said it was waterbased and to use Solvistrip. They suggested I wasn't putting enough on. So I tried applying until dripping, let that soak in for an hour, then put a load more on.

That did a much better job. The paint became soft enough to remove with a jet washer without damaging the bricks. Problem is it was still plasticy and time consuming to remove, and the jet washer just moves the paint somewhere else - what didn't stick to my best trousers stuck to the fence.

With more experimenting I've found a way to contain the paint. Put a load of Solvistrip on and then covered it with a cotton polishing cloth (an open weave stockinette type cut to make it single layer), then a bunch more Solvistrip on top of that.

After an hour the paint was soft enough to stipple the polishing cloth into the paint by hitting it with a scrubbing brush. The idea was to make the cloth stick to the paint better than the paint was sticking to the wall (not well).

After 48 hours the exterior of the cloth was dry and I ripped it off the wall. It took most of the paint with it leaving it on an easy to dispose of cloth and not the fence.

The bits that are left are still very soft so I might try leaving the cloth a little longer for the next experiment. I just want the paint a little soft and well stuck to the cloth. For the remaining paint whether a second application in the same way as the first is better than the conventional stripper and jetwasher method on the remains will take further tests. Which I can report if anyone hasn't become bored to death already. Most of the plastick gooey stuff has gone so should be easy.

PS - Tried Peelaway 7 too. That's still on the wall. Paint underneath is soft and sticky but there is no obvious removal process that won't coat the fence.

 

[andrew gayton]

I have used a blow torch and scraper with good results. Try it, you will be amazed.

 

[malcolm]

It's an old post but I thought I'd add an answer instead of just asking questions. The answer is paint stripper and a steam jet washer (DOFF), and to get someone else to do the job.

I ended up completing the barn with paint stripper and a cold water jet washer but that made a horrible mess and it took about 10 horrible days. Recently I called in professionals recommended by Strippers of Sudbury to strip the paint from the house. They used the DOFF steam washer which generally seems to have caused very little damage to the brick and is very quick. Stripping the whole house took a week.

Cost about £35/m2 (plus VAT) and worth every penny.

 

[garnett]

Hi

I can whole heartedly endorse the above. I have grant aided paint removal from buildings and the only way to successfully do it in a sensible timescale is the DOFF System. The only caution I would give is regarding the pointing. Doff will wash out soft lime pointing and leave any cement. I had a building butchered with a builder and an angle grinder after cleaning. This is a task that really should be done by hand.

Good luck

Garnett

 

[malcolm]

Our pointing survived DOFF stripping fairly well, though the pointing on the gables had receded by 10mm before the walls were painted so they need doing anyway. (I have slightly more overhang on the roof now which will hopefully help protect the brickwork a little more). I will hopefully be able to only selectively re-point the side wall which has been protected in areas where the guttering worked.

I've got a couple of guys on the job of re-pointing. They are using hand tools (mostly a screwdriver) to rake out and square the joints and the bricks are being well preserved. It's a time consuming process costing me about £50/m2, but the work is being done to an excellent standard.

 

[plasticpigeon]

The guys who used doff to strip the stonework on my house were idiots and blew holes in the stonework with the doff machine. I guess it works well when used by skilled people.

 

[erikwoolf]

Does anyone have pictures of before and after applying DOFF? We have a couple of walls that need stripping the quotes that I got for chemical stripper and steam washing they said we will lose part of the pointing. Did anyone had the surface of the bricks damaged by using DOFF?

 

[malcolm]

I didn't have any brick surface damage that I would put down to the paint stripping but did have some damage to a couple of sandstone window sills. Some photos of the brickwork lower down on this page: https://www.the-salutation.co.uk/blog/2015/04/ It's well worth a try asking the operator to be turn the machine down and go slower with any sandstone.

I repointed about three quarters of the walls after stripping. I've included a photo below of the remaining quarter where the pointing was originally a trowelled finish at the top of the photo but aggregate has become exposed lower down after the DOFF stripping. The pointing wasn't recessed enough to bother repointing.

Elsewhere the walls were more exposed. The pointing had deteriorated before the walls were painted and the paint had caused them to be soaking wet for years which may have made the mortar soft. The DOFF blew maybe 10mm of soft mortar off those walls and they all needed to be repointed.




Here's a photo of a sandstone window sill. It has had some time to weather and doesn't look quite so bad now, but the vertical lines are DOFF pressure washing marks. It wasn't removed for that. It came out because of previous abuse and a crack.

 

[erikwoolf]

I didn't have any brick surface damage that I would put down to the paint stripping but did have some damage to a couple of sandstone window sills. Some photos of the brickwork lower down on this page: https://www.the-salutation.co.uk/blog/2015/04/ It's well worth a try asking the operator to be turn the machine down and go slower with any sandstone.

I repointed about three quarters of the walls after stripping. I've included a photo below of the remaining quarter where the pointing was originally a trowelled finish at the top of the photo but aggregate has become exposed lower down after the DOFF stripping. The pointing wasn't recessed enough to bother repointing.

Elsewhere the walls were more exposed. The pointing had deteriorated before the walls were painted and the paint had caused them to be soaking wet for years which may have made the mortar soft. The DOFF blew maybe 10mm of soft mortar off those walls and they all needed to be repointed.


View attachment 10849

Here's a photo of a sandstone window sill. It has had some time to weather and doesn't look quite so bad now, but the vertical lines are DOFF pressure washing marks. It wasn't removed for that. It came out because of previous abuse and a crack.

View attachment 10850

Thank you Malcolm it is good to know what to expect, my assumption is that the most of the wall surface will need to be repointed after the DOFF.