Rendering over pebbledash

[asimon]

Hi all,

I previously added a post titled "Pebbledash removal companies South East London / Croydon", but i am still struggling on what to do, another build that I came quote, advised a lot of the damp problem seem to stem form the drainpipes and guttering whereby water is getting into the cracks in the pebbledash, and various holes in the walls.

He has advised the following, remove the pebbledash on form the form of the rear extension, see first image of house, and render over the rest of the pebbleddash, would like to hear your thoughts, is it a common practice to render over pebbledash / ok to render over pebbledash.

Pictures can be accessed from below:-

https://www.dropbox.com/sh/d953f21cy2jz7nd/uYGzEYoYVh

Following on from he above, would welcome recommendations for builders / tradesmen, to do in external and internal building/decorating working SE London

 

[worms]

My instinct on these quotes would probably include the words touch and barge pole. But more knowledgable members with less cynicism of the building trade will be able to give you better advice.

 

[rogerh]

I'd be tempted to remove a section to see what condition the brickwork's in underneath before making a decision on the best option. Presumably your neighbour's house has the original finish.

 

[plasticpigeon]

It would be nice to get it back to brick and then re point. You might be lucky, it might fall off in sheets, but you might be unlucky and have it pull the face of the bricks off. Worth a try i would think.

 

[asimon]

plasticpigeon, I have thought about going back to brick which I would prefer, the quote for this i quite expensive fro a company that was mentioned on this forum that specializes in brick work renovation called Mahon.

 

[rogerh]

While the brickwork's condition is unknown isn't any quote likely to be for a worse case scenario?

 

[88v8]

Have you tried knocking the pebbledash off?

Ivor

 

[Flyfisher]

. . . . another build that I came quote, advised a lot of the damp problem seem to stem form the drainpipes and guttering whereby water is getting into the cracks in the pebbledash, and various holes in the walls.

Is this all about curing a damp problem or is it primarily cosmetic? (Could be both I suppose).

If the damp problem referred to really is a result of the drainpipes and guttering not doing their job (i.e. not keeping roof water off the walls) then doing anything to the pebbledash might not solve the problem. That's not to say that a coat of cement-based pebbledash is doing no harm, but first things first.

I would recommend venturing outside in the pouring rain and watching the gutters and downpipes for a while to see what's really happening.

 

[asimon]

The issue is both to damp with Damp and the cosmetic side whereby the rear extension the Pebbldash has definitely gone with various cracks, and causing the wall inside (kitchen) o be damp, also eclectically, the house has a number of holes, and aesthetically would prefer bare bricks, or smooth render.

Is it wise / recommended or known practice to render over pebbledash if it is sound, which would be cheaper I presume or could it cause problem s in the future, or would it be preferable to take off all the Pebbledash then render, fell free to have a look at the images post and your thought on what you would do

https://www.dropbox.com/sh/d953f21cy2jz7nd/uYGzEYoYVh

 

[88v8]

I think you should try hacking off some of the pebbledash - is it pebbledash or roughcast? - and determine for yourself whether it's going to come off cleanly. If it's well adhered there's no reason not to render over it if you wish.
There's also the fact that it's been painted, introducing another layer which may or may not have good adhesion. The paint will presumably be non-absorbent, but it is possible to render over a non-absorbent surface by coating it with pva, then applying another oat of pva and rendering while the second coat is wet. No good however if the paint is peeling off.

If as it appears a number of holes have been knocked for the plastic drainage, then that would impair the appearance of the brickwork if it were once again on show. There is also the possibility that the brickwork has been hacked about to insert that ill-proportioned downstairs window. Do I also notice the shadow of an old window above the side door? Again one wonders how that brickwork would look if it were exposed. Rendering is often done for a reason.... a pity in this case as the brickwork next door looks rather pleasant, and I imagine there is a nice flat arch over the door.

I guess you are somewhat planning ahead here - it would seem rather illogical to re-render before getting rid of that awful plastic drainage, the cable across the back, and the plastic windows & door of course.

You mention cracking, can't see in your pics. If the cracks are from structural movement, then they may well reappear, depending on the cause.

Ivor

 

[Zebra]

Well you could repair the cracks, either with a dollop or two of cement mortar, or with paint, or silicone, whatever, and see whether that helps with the damp issue. Of course, walls take a long time to dry out - the rule of thumb I believe is an month per inch thickness of wall, so if you have 9 inch solid walls that'll be up to nine months before you have total dryness. If the cracks in the render were the problem.
Like others, I would be very keen to eliminate any water ingress from guttering, before committing to another course of action.
I note that all the quotes mention the inclusion of waterproofer and hardener, even the one which includes lime in the mix, so this is in no way a breathable traditional lime render. There may be nothing wrong with that, but I think I would want to find out exactly what was causing the dampness before embarking on a very expensive non-breathable, waterproof coating for the house.
Are your walls nine inch solid brick? Is the damp due to condensation? Is it rising up the walls from the ground? Is it getting in around poorly maintained windows? It could be that you spend all this money on a new coat of render, non-breathable like the last one, and you still have damp walls

 

[Keithj]

My worry would be whether or not the pebbledash is "blown". We had a small blown area on the house we used to have, half way up a mountain in North Wales. A local builder agreed to fix it for us. When he hit the loose area with a hammer, it fell off - as did another large area of pebbledash followed by a few square feet of the wall. Damp had caused enough damage that the (concrete) pebbledash had lost adhesion to the lime used to hold the granite in place.

The repairs involved rebuilding the wall, lining the chimney (the source of the water ingress), then pumping the wall full of some chemical compound. I don't know now whether that was the best solution, but it certainly made that wall bombproof. A different more experienced local builder took over, and fixed all the damp problems we had, one by one.