Render repair

[Doug71]

Can anyone give me any tips on what to do with this rendered wall/gable end?

We are getting the flat roof done but I think the rendered wall needs a bit of attention so obviously want this sorting before the flat roof.

Most of the render is not too bad but there are one or two cracks in it, some patches sound hollow behind the cracks.

Can it be patched/repaired, if repaired should it then all be coated with something?

You can see it's a really awkward area to work on.

Thanks in advance, Doug

 

[doctor Bob]

Hi Doug,
I have a rendered garden wall, if it's got a hollow sound water has got behind and frost got to it. It needs knocking off.
I take all loose stuff off and then cut an edge with a grinder and re render. never perfect but not bad.

 

[baldkev]

After a successful patch up job, probably a good idea to fungicide and paint it with weathershield or thompsons waterseal or similar.....

 

[morturn]

If this was my house, I would just repair it in the places it come loose. You can tell by tapping it.

Why would anyone want to paint it, other than finding yourself another maintenance job every five years or so? Cement render is a perfectly durable and weather resistant surface that ages with the property. As long as it is sound and attached it will be fine.

 

[SammyQ]

I had hollow sounding render patches on two gable walls 28' x 30' for 25 years. They stayed intact because I repaired the 'flaunching' at the very top, allowed water runoff, and coated the whole surface with a high quality plasticised paint/treatment after I had Vee-angle ground and filled the worst cracks.

Just sayin. I was too hard up to strip and re-render that area.

One wall faced due north, no ingress, no damp, despite it being 9" solid wall from 1903.

Sam

 

[Woody2Shoes]

That render doesn't look too bad at all - but as already said, the best way to check is by tapping it.

I'm not sure where the prevailing weather is from, but that gable wall is probably protected to some degree by the roof on the right - although the valley gutter is less than ideal (the lead flashing could easily be twice that size - I might be tempted to add another piece(s) of lead, one brick course above the existing flashing, folded down over the existing flashing/upstand) water rushing down off the right hand roof could easily hit the vulnerable joint between the existing lead and the render (which is perhaps not as weatherproof as it might look in the photo).

Render is easy enough to repair, you just need to open up a crack (with a cold chisel or angle grinder) so it's about an inch or so wide and apply new render (sharp sand and cement in a strong mix). You could paint the render with something like this https://www.wickes.co.uk/Wickes-Water-Seal-for-Vertical-Exterior-Surfaces---5L/p/600336 if you wanted to, but it will dry out better as is (on the basis that water will get into it, you want it to have an easy way out). As you say, access is not easy - the trickiest and most potentially expensive aspect.

Has there been a bit of new lead where the downpipe discharges?

PS I really would be focussing my attention at the bottom edges of the rendered wall and the whole valley gutter arrangement (there does seem to be a bit of possible water staining along the bottom of the render, for example)!
PPS As a minimum, I'd be improving the seal/joint between lead and render e.g. WATCH NOW: Lead Sealant from Midland Lead | Construction News (also, see how much taller the lead flashing is?)

 

[owen]

I wouldn't patch it, if you're gonna do the job, do it properly and get it stripped off and re-rendered.The lead flashing at the bottom looks like it could be made higher too, the water coming off that roof could be splashing above the current flashing by the the looks of it. You want to seal the lead in with leadmate and hall clips

 

[clogs]

a better shaped /deeper gulley will help....depends how much lead is in the wall but doesent look that good on the end....
the lead should be no less than 14" up under the tiles and if u use slate, same amount up the wall....read on...
If the wall faces North or West I'd be using roofing slate......quite normal in some parts of the country.....
qual battens and st/steel fixings...
fit and forget.....
cement render on any other facing.....East or South......
I have used Weber products pronounsed (Vayber) before in diff situations, (watermill) it's available in colour as well.....
once prepared prop this stuff wont come off even with SDS chisels....not cheap tho.....
If u go ahead with render, personally I'd take it all off and start again.....

is that a seperate property next door......makes the whole job tricky....
make sure who ever does it is register'd/ good reputation locally with insurance.....

 

[Flynnwood]

Google silicone enhanced render 30 year BBA approved

 

[Richard_C]

I have a similar dilemma with the valleys on my roof, all 4 need attention especially the bedding of the roof tiles along each side. One valley has started to leak. A roofer gave me a quote for a 'fix' and for a proper job with new lead valleys (current ones are 35 years old glass fibre). Access is awkward to 2 of them, and the cost of the scaffold made it pointless to do the fix: while the scaffold is there it makes much more sense to do it properly rather than have to come back in very few years. If you are planning to stay, and can afford it, a proper job might be better value long term.

 

[sammy.se]

is your house built with lime or cement?
If lime, then re-render with lime, ideally.

 

[Doug71]

Thank you for all the advice, some great points in there.

I was going to get my roofer to look at the valley as there are a few bits of Flashband stuck on it in strategic places as if the lead has split. I will have a closer look at the lead/wall detail, makes sense for it to go higher. You can't really see on the photo but the water off the front roof also comes on to the valley, the front gutter has just been turned to come through the top of that parapet type wall at the end, the water just runs out and I guess blows all over the walls etc.

The rendered wall faces East so doesn't get much weather, I will go up again and see how many loose patches there are. Luckily we do own both properties which helps but still a very tricky area to work on.

 

[Woody2Shoes]

Here's an example off Google showing a better set of details - wider and tapering gutter, with individual bays (so no piece of lead is longer than about 1.5m which would otherwise risk lead damage due to thermal movement) and a decent fall along the length (to get water off the roof quickly - this example is highest in the middle and falls both ways - something you might consider if you decide to redo the whole thing) plus a cover flashing chased into the vertical wall, coming down to protect the lead upstand at the bottom of the wall.

 

[Artiglio]

To me its one of those , “leave alone or do the full works” jobs that’ll grow arms and legs when you get into it.
All depends on the timescales of how long you’re intending to keep the property and ,if long term ,any other plans you might have.
Whilst it may not look the best if there’s currently no water ingress or damp issues leaving it a while longer probably represents no problem.
I’m near the coast and would be more concerned about gulls building a nest and blocking water flow.

 

[lexi]

I would suspect that render is facing S/W and has been done to alleviate water ingress.
Be aware that in getting any roughnecks to cut it off, a power chisel can damage brick. So tedious to take it off with hammer and chisel, but less damage. If it were a source of ingress and was bossed, you can stud wire lathe on and finish with three coats of render. You can use SBR through traditional sand/cement or get a Waterproof Polymer system in a ready mixed form. Do that and you can forget about it. If it isn't showing dampness, just patch it.

 

[Phil Pascoe]

In my old house I had yards upon yards of cracks in the render. A three storey west facing house in West Cornwall, so no stranger to dreadful weather. I opened them all up with an angle gringer, washed the dust out and filled them with floor tile adhesive. Fairly quick setting and easy to sponge off. Fifteen gallons of oil based Weathershield and it hasn't been touched in the last ten years.

 

[owen]

View attachment 93278
Here's an example off Google showing a better set of details - wider and tapering gutter, with individual bays (so no piece of lead is longer than about 1.5m which would otherwise risk lead damage due to thermal movement) and a decent fall along the length (to get water off the roof quickly - this example is highest in the middle and falls both ways - something you might consider if you decide to redo the whole thing) plus a cover flashing chased into the vertical wall, coming down to protect the lead upstand at the bottom of the wall.

That's good, but worth noting the lead should be fixed in using a leadmate sealant not pointed as per your pic.

 

[Woody2Shoes]

That's good, but worth noting the lead should be fixed in using a leadmate sealant not pointed as per your pic.

I think that the lead should be fixed in position by lead wedges or stainless steel spring clips. Weathersealing the joint can be done with mortar or low modulus silicone.

 

[Doug B]

If it were mine Doug it would be covered with some cladding, there’s some really nice gear out there now with the added bonus of if the jobs done right you can forget about it. Patching old cement render can be very unpredictable & invariably leads to further maintenance work.

 

[owen]

I think that the lead should be fixed in position by lead wedges or stainless steel spring clips. Weathersealing the joint can be done with mortar or low modulus silicone.

Yes hall clips to fasten it, I meant to seal it sorry. I don't think mortar is acceptable anymore but I may be wrong? I thought mortar could only be used on really wide joints and even then the top and bottom of the mortar where it meets the lead and the brick/stone had to be sealed with leadmate