Removing weathershield type paint from cement or lime render

[tobydog]

Would appreciate any advice on how to remove Dulux Weathershield type paint from cement or lime render. Now that we have discovered lime render actually exists under at least some of the modern coatings / panels, I would like to start working out how to get rid of it, if possible. Thanks.

 

[middi]

If you have masonary paint on cement I don't see the point of removing it, you might as well put some more on and smarten the place up. ( unless you prefer the look of bare cement render). It is extremely hard work anyway, you need to scrape it or blast it off.

As to removing it from lime render, well, you need to remove it for the lime render to function as intended. Lime render is much more permeable and adhesion between paint and render is not extreme as in the case of cement . If you are lucky ( and the render is slightly damp) you may be able to peel most of it off. You can scape it off ( easier then doing it on cement) but score marks will be left in the soft render.

JUst tedious work I am afraid.

( just find the person that applied the paint and shoot him, it will make you feel better )

 

[Nigel Watts]

Lime render is quite soft. Mechanical or abrasive methods of removal of paint are best avoided. Sand blasting (which my neighbour tried) can be positively disasterous. Chemical strippers are probably best.

This is worth a read: http://www.lbhf.gov.uk/Images/GuidelinesonrepairsStPetersSq_tcm21-112603.pdf

My 1840 stucco semi in North London is currently having its paint coatings stripped. Under the modern Sandtex and emulsion are many layers of linseed oil based paints. Several applications of chemicals are needed to get through this lot. My contractor is also using high pressure steam.

 

[tobydog]

Middi / Nigel - thanks for the advice. The reason for the removal of the paint from cement is because when the sole plate work is done at the front of the house we will be removing the first 3 or 4ft of cement render and replacing it with lime. This will be lime washed, however, we can't afford to remove and replace all the cement above which is painted in weathershield stuff. I was hoping we can at least remove the paint and give it a finish that goes some way to blend it with lime wash.

We don't know how far the lime render at the top of the gable end extends downwards or whether there is anything other than paint on top of it.

I would love to shoot the person / people who painted it but I would rather shoot the builder who did the cement render in the first place. Prevention is better than cure although I know the guy is now in his 80's so not very sporting!!

 

[Flyfisher]

I would love to shoot the person / people who painted it but I would rather shoot the builder who did the cement render in the first place.

In their defence, the detrimental effects of cement render may not have been fully appreciated at the time the work was done.

The timber-frame part of our house was re-rendered in the 1930s and I assume this was when cement render was applied. In those days I suspect that cement was regarded as a modern technological marvel - easy to mix, quick and reliable to set, strong and long-lasting etc. The importance of permeability may not have been considered.

 

[tobydog]

Alas that's still the view of many builders today. The builder who did our extension was excellent and the foreman still comes back and does odd jobs for us in his spare time. Costs are great because he uses all the off-cuts from other projects. I was too mean with ours and squirreled the off-cuts and leftovers away as soon as they were finished with. I knew I was paying for them anyway!

Unfortunately the foreman was the one who said not to worry about the cement render inside the old part of the house. I subsequently found out there was a nightmare going on underneath. We now know what jobs to ask him to do and when we need a 'traditional' builder.

 

[robgil]

nb510 might shift it.
http://www.stripperspaintremovers.com/
It shifted sandex for me.

 

[Pford75]

Seconded. NB510..... With a hot water pressure washer (cold is pointless as it takes ages). I've done an entire (reasonably large) house.

 

[tobydog]

Thanks for the extra info. I need to do some more exploratry work to see exactly what I have under the paint because it varies in different parts of the house.

 

[88v8]

Sand blasting? Arrrrgh :shock:
However, a company specialising in plastic media blasting on old houses will be able to shift it without damage, and exactly this job is on my agenda for 2012.
Your CO will be able to recommend approved companies, as blasting requires LBC.

My CO has recommended for instance:
http://www.tridentblasters.co.uk/
and
http://www.protinus.co.uk/

I can also recommend
http://www.blast-cleaning.co.uk/index.php?menuid=50&component=content&task=article&articleid=39&categoryid=9
who do both buildings and classic cars.

Slightly OT, for repainting the render & timber, the CO recommended a lime slurry coat to fill any cracks, followed by limewash, with the option to apply hydraulic lime paint to the timber for that Victorian black n white look.

Ivor

 

[tobydog]

Ivor - if the budget allows it would be great to get someone in the do the job. The budget, however, (if there ever really was one) is down to what we have in Percy the Pig at the moment so sometime next year you may hear me moaning about tennis and/or golfers elbow and not a ball in sight!

 

[88v8]

I reckon to have spent 30,000 (thirty thousand) hours restoring and improving our present house, which we're now selling and eventually one becomes aware that life does not stretch endlessly ahead, so now on the notnew house I'm employing various people to do things that I would in the past have done myself, simply to get them done so I can hopefully spend rather more time on things I enjoy. The budget, such as there was, has been blown many times over hehyo, and now as one job inexorably generates another we have four different building companies involved. I try to turn a blind eye to some of their workmanship, reflecting that much of the work done on the house in the past was less than brilliant and some aspects of its original design were frankly c**p, but it's still standing....
On the plus side, doing everything oneself, plus never buying a new car or anything on tick, and taking just one week's holiday away (UK only) eventually adds up to a nice pot of money over 30+ years. At least it has for us, hopefully will for you.

Ivor

 

[tobydog]

I must be doing it wrong. I'm trying to do as much as I can myself and I still don't have the proverbial pot to you know what!! I must stop contributing towards the cushions and smelly candles.

 

[Pford75]

Sand blasting? Arrrrgh :shock:
However, a company specialising in plastic media blasting on old houses will be able to shift it without damage

That's a little too unequivocal for me. It may be that plastic media blasting offers better results than sand or grit, but you cannot guarantee that the substrate will not be damaged. Personally, I'd want to see several test patches before committing to doing an entire building.

 

[JoceAndChris]

Nothing really useful to add to this (except I've read you can put limewash on top of non-breathing paint to match up your different bits, and I've had success putting distemper on top of lightly sanded modern emulsion inside the house) but, anyway, lots of the comments in this thread have made me smile today, and I badly need cheering up.

I so relate to the 30,000 hours, andthe poor old empty Percy Pig. Good luck with all our endeavours; may they all be quick, cheap and beautiful (impossible!).

 

[Keithj]

One thing that I was assured doesn't work is trying to get a reliable "join" between concrete and lime render (such as half way up a wall panel). We have some panels still rendered in concrete - but only high up the wall, and none of the wood around them is showing signs of distress.

We spent a large pot of gold removing the concrete where it had caused problems, replacing all the sole plates (yes, all) and some of the studs, then lime rendering. Job done, and it looks good.

 

[tobydog]

I remember seeing the photos. The 'join' is a concern and it may require us to take the cement off to at least first floor level to limit the effects of movement in the frame (if possible). I've bitten the bullet and I'm meeting with Rick Lewis of Traditional Oak Carpentry later in the month to better assess the work and budget. We know we can't afford the whole of the frontage (extent of sole plate) so we are doing one side of front door (the shortest) first. This is the part I've already opened up. Work to happen next spring. Will also take the opportunity to properly insulate the front wall between the studs so we mat get some payback over the next 100 years!!!