Thanks for this video. I'm trying to get rock hard cement render off a 1680 limestone internal wall by hand, and this has given me some hope! It's astonishing what people do to these old buildings. They need to breathe! What isn't covered in cement in mine is covered in hardboard. Plasterboard nailed onto original beams... Happy days!
Thanks and You’re welcome! It just takes ages and there is no magic solution and some damage seems inevitable unfortunately. Keep going with it and as you make progress you gain motivation. Good luck!
Removing all the cement render and replacing with Lime is only going to partly resolve your damp issues. Next you need to address the water that is getting into the walls from the ground outside. To fix you need to install a French drain around the entire perimeter of the building at the base of the outside of the wall - ensure the slotted drain pipe is placed at a minimum of 100mm below the interior floor level and backfill with gravel around the pipe only. Ensure you have adequate fall in the slotted pipe to drain away from the building. Once done this will allow your walls above to dry out.
Hi Paul - Totally agree. The ground levels are stupidly high in some areas, and a basic drainage channel was dug around the perimeter a while ago, to at least aid the start of drying the walls, prior to a proper french drain being installed later (there are a lot of other ground works to be done first). There has been a lot of penetrating damp as the guttering is also knackered, water has been getting in past the windows and down the chimneys and a lot of salt has moved inwardly through the walls, causing interstitial damp, so you’re right, it’s not as simple as just remove render and re-point! Once the ground levels outside have been addressed, the new lime internal floor slabs will be laid to ensure they are higher. The foundations are also very shallow in places so it has to be carefully considered
Great comments here - same situation in my house! We're planning some drainage to be put in also It's good to read these it helps with communicating with builders to have some entry level knowledge about the fix needed !
I lived in one that was right up to the pavement, so this was not an option. Went for chemical injection for insurance but wasn't totally effective due to all the salt in there from the road. Sort of a no win situation.
@@r.perkins2103 No Chemical injection absolutely never ever works. The salts came from the moisture that was trapped - anytime you have cement / Gypsum you get efflorescence from the salts. The correct way to deal with the situation is as described in my first comment. Btw the chemical injection will also structurally damage the walls over time.
I can see there's a slate DPC there, it could be that the bridging of it from the outside with the render and also the inside (where it looked like the plaster bridged it) is causing most of the issues
Did you cry after that discovery ? ! 😂 Wow that’s a task on its own…. But there’s nothing like rebuilding, regeneration and rejuvenating….. it gives so much satisfaction I’m trying to get half metre(or less) of render off a brick lintel and it’s pulling big lumps off the bricks 😢 Good video I might try that comb style SDS chisel myself x
I think Peter Ward said something that chopping the cement off like that can remove the outer harder layer of the brick. So my inclination would be to re-render it in lime instead of just using a lime wash. I feel like the render would protect the bricks better. Seeing the inside of the walls fall apart at the end was just heartbreaking.
Absolutely correct and an unfortunate side effect of remedying the situation. Re-rendering in lime hasn’t been entirely ruled out but, since that is added cost and work, once the brickwork has been re-pointed with lime, it is likely I will use a silicate mineral paint which creates a carbonated mineral bond with the brickwork. I like to think of it as the NHL of the paint world or akin to a limewash with a pozzolan added(?!) A number of conversations with silicate paint manufacturers e.g. Earthborn suggests that this will help consolidate the surface of any damaged brickwork - a bit like replacing the hardened layer of brick that was removed. It also remains breathable and provides weather protection, much like linseed oil would in a Limewash.
@@therestorationstation5475 I have an outhouse with similar problems when I removed the cement render (harder still than yours) a lot of the weather face on the bricks came off or had already spalled. I managed to repoint the joints but the winter weather came early and I had to leave it till frosts finished. The bricks are continuing to spall and the surface is so rough that I'll have to lime render to get a better surface. I'll either lime wash or paint with a mineral paint (expensive!). If only the builder had any clue how to mix proper mortar and use a lime render originally it would have prevented so many problems and effort needed to rectify. Best of luck with your task - at least mine isn't part of the actual dwelling.
Mine looks a lot worse on the outside - yours is so much worse on the inside! You've persuaded me that the £40 for the scutch chisel is worth it for the 50ish m2 I need to strip, especially as ours is going to be insulated so I don't care about the face of the bricks. Thanks.
As far as I can see, the golden rule that mortar and renders must always be weaker than the bricks is constantly ignored or is unknown by some "builders". In case of shrinkage or settlement any cracking must only occur in the mortar joints and render and not the bricks. Using stronger renders means that once water has entered the wall it actively enhances spalling and disintegration of the bricks by providing resistance to the forces of water expansion during freezing. I can see that your render is so strong that the bedroom window sill has been cracked too. No wonder use of lime is coming back into more frequent use.
This is the correct issue. There is nothing wrong with cement mortar when mixed correctly for the purpose. You should never use a 3:1 mix for walls of any kind but some people do. A 5:1 or even 6:1 for cement is much better and won't cause issues. You can even premix the cement with lime at a 1:1 or 2:1 mix for especially soft bricks or stone. Cement resists weathering better than straight lime. There is a reason we moved to it initially. Its just bad brickies, or non-brickies doing masonry they shouldn't be. Cement also slows the movement of water. I prefer it in mortar to slow the vertical movement of water. Cement render should never be used IMO. You want to keep the horizontal breathability as high as possible. Lime is great for that but I'm hearing good things about silica based products as well. Time will tell.
Nice video sir. How would you go about removing a non breathable paint from brickwork on an exterior wall? Would it just be about hammering it away or would you go for applying a product?
I’m so confused now. So rendering is bad? Should we never render then? I have some leaks and have been advised to render… would have liked more explanation on this video about when to render and if there is a correct way to render to prevent damp.
Hi Jes, sorry if I have confused you. The takeaway here is that cement render (and also cement pointing) is not ideal on a house built with solid walls and lime mortar. This is because, unlike lime mortar, the cement is not breathable and does not allow moisture to move through the walls and evaporate. Instead it gets trapped in the walls causing damp issues. Cement render is also not flexible so it will likely crack as an older building moves and settles. These cracks can allow in rain which cannot escape, exacerbating the situation. Just to be clear, rendering is not bad and cement render is not bad in the correct context. However in this instance a breathable lime render should have been applied. As an example of when to render - It may be necessary for me to re-render these walls with a lime render, after re-pointing with a lime mortar, if the soft bricks turn out to be too damaged by the removal of the hard cement render, or by the years of moisture it trapped within, to simply re-point with lime and limewash over. The lime render would help consolidate and protect the brickwork whilst allowing the wall to breathe as it should. It would then be painted with a breathable limewash paint. (Acrylic / non breathable paints should not be used on this type of building). As for your leaks, I can’t really comment as to whether rendering is appropriate in your situation. However, if you have a traditionally built house with lime mortar, I would immediately discount the opinion of any builder suggesting you either re-point or render with cementitious products to solve damp issues. If your house is of more modern cavity wall brick and block construction built then rendering with cement may well be appropriate but in either case I’d be trying to understand more about the cause of the leak / damp. Hope that is of some use? Pete
@@therestorationstation5475 A big no-no I was told by a damp surveyor is rendering over the DPC and in effect bridging it and allowing water to travel upwards via capillary action. So when rendering with anything it can also be a good idea to stop above the DPC or use a drip beading installed at the DPC height to essentially build a DPC into the render layer.
Yes I’m looking forward to the time this is a distant memory! Good luck with the pebble dash… I’m not going to sandblast the bricks for a couple of reasons.. Firstly, they are very soft handmade bricks so I’d not recommend sand blasting as it may damage, or in this case compound the damage, to the brick faces. The irony is, I am all too aware of the damage I am already causing by having to remove the render. It’s a catch-22 to remedy the damage caused by the damp caused by the render…! Secondly, and because of the damage already incurred, I have two options.. Either re-render with lime (which is time and cost prohibitive for me) or re-paint with a silicate paint which is both breathable and will help consolidate and protect the soft brick faces. Whichever option, there would be no need to remove the cement stains as they would be covered over. Most important thing is that the cement is removed from between the joints and the walls can breathe again
@@therestorationstation5475 I can still smell the damp behind the plasterboard. That will stay with you for life. Luckily in my case, the house is stone with brick only on the corners. Looking forward to removing the dash but not the sandblasting bill. I reckon it'll cost me 2 or 3 hundred to repoint stone, add another 1k or so for the sandblasting 😐 wish I could go back in time and stop them from doing it in the first place!
@@cocospops9351 fortunately the actual smell of damp has mostly disappeared, but You’re right, I’ll not forget the smell and how soggy the plasterboard was. I do wish I could turn back the clock on the house and do often wonder if they didn’t appreciate the damage they would cause in the future, or whether they just didn’t care knowing they would be long gone by then. Have you considered re-pointing it yourself? What type of stone is it? If it’s a soft stone e.g. sandstone be equally cautious of sandblasting..
Hi Robert. About halfway - To be honest I’ve started being pulled in all directions with this project so I’m tackling it in small sections since I won’t be properly re-pointing the outside until next year realistically. Those stupid idiots!!
Hiya John - The plan is: 1. Let the walls dry out properly (at 1month per inch of thickness so 9 months roughly). 2. Re-point with Lime Mortar. 3. Depending on how things are looking either, preferably, paint with a breathable paint (lime wash or silicate paint) or re-render with Lime Cheers Pete
Lift the old parquet, carefully hack up the cement screed so as not to damage any original flooring below. Assuming the original floor is clay pamments (tiles) laid on bare earth then I will reclaim these to re-lay upon a new insulated floor. Ground levels between each section of the house need addressing too. Budget and practicalities will dictate whether underfloor heating is fitted. Will do videos in due course 👍🏻
Hello mate, great video by the way, I wanted to ask you on an estimate of how long do you think it takes for a square meter of the wall surface to be cleaned off the cement render by hand and chisel and if it’s possible at all?
id say an hour or two depending on how hard it is and by hammer and chisel. but yes its definitely possible, you'll just have to be patient and push through the pain of giving up ahah
What a horrible job it is. It took me 3 solid days to remove the render off the back of my house and I was using a heavier duty pneumatic breaker to get it off, on a low setting so as not to damage the walls. Very heavy to use compared with your Titan drill. Not a job I'd ever undertake again!
I'd hope there is a special place in hell for the bloke who put on that render! By crikey you have a project on your hands - but great satisfaction when you get it sorted.
Did you cry after that discovery ? ! 😂 Wow that’s a task on its own…. But there’s nothing like rebuilding, regeneration and rejuvenating….. it gives so much satisfaction I’m trying to get half metre(or less) of render off a brick lintel and it’s pulling big lumps off the bricks 😢 Good video I might try that comb style SDS chisel myself x
