render with sbr

Joined
1 Apr 2014
Messages
67
Reaction score
0
Location
highland
Country
United Kingdom
Hi, I need to repair some render at the bottom of my garage wall, it's not a lot so I just bought three 10kg buckets of sand and cement mortar mix, the kind you just add water to.As the reason I am doing it is that I am having problems with water ingress someone told me to get some sika sbr.My question is when using this as a bonding agent do I need to make up a slurry with cement or can I just paint it onto the wall then add some to the mortar mix and apply, thanks.
 
Sponsored Links
Are you sure that the water ingress is due to the damaged render, as the bricks underneath should keep the garage dry. If you're sure of the problem, then you can just paint on the sbr, and then go on with the render when it's dry. My mix the sbr into a slurry when the substrate is too slippery to take the render.
 
I think that the water ingress is due to this but cant be certain, the garage is block and not very dense ones at that.The ground level was too high on one side and it is very wet around here and the water had damaged the render and started to wash the mortar out of the joints.The plan is to fix the render and then paint it with black jack dpm, since the weather was good today i went for it as the forecast was dry all day.I painted it on and did the render repair and made a shuttering and added some concrete where it was really bad and now guess what, its freezing here, first time this winter.Typical, hope its going to be alright.
 
Cement render can be done down to 5C, so depending on how freezing it was you might have got away with it. Post a picture if you want, and we'll see if there are any other issues such as ground levels being too high etc.
 
Sponsored Links
Here are some pictures of the wall, hard to see how high the ground level was but if you look at the 3rd picture you can see the pile of gravel that was pulled back and i have also removed a lot of earth from there.Right at the back i would say the ground level was about 8in above the footing, the cowling was to cover over one of the blocks i drilled previously to get some ventilation.On the inside of the garage it looks like the moisture is tracking up through the mortar.


wall2.jpg


wall1.jpg


wall3.jpg


wall4.jpg
 
Exactly where is the DPC in relation to the ground level. If the water is tracking up the mortar joints, then you'd need to inject a silicone DPC in the mortar to stop the moisture rising, but you'd also need to hack of the lower section of the render, and redo it with a waterproofer in it.
 
Not sure where or even if it has a damp course, will painting it with dpm bitumen paint not in effect make the render waterproof.its only in the one back corner which is why I was thinking it was the ground level.
 
If you've got no DPC, then moisture will very likely track up somewhere, even if you paint the lower section with bitumen paint. Your render goes right down to the foundations, and it'll creep up through there, so you'd at least need to take off the lower 6" of render first. In fact, I'd be inclined to take off the render to a suitable mortar joint, drill and inject with a silicone DPC (all DIYable stuff) and then apply the bitumen paint.
 
Well after drying out the floor it has become obvious that it is the wall its coming in, just need to wait for a dry weekend to hack the old render off at the bottom and put some new on with sbr in then paint it with blackjack dpm. Right at the back you can see in the first 2 photos i posted that the concrete steps up where the post is so i think ill have to smash the concrete around the post to get in at the wall behind it to sort it.
wall10.jpg
 
Suppose the other option is to just tank the inside with tanking slurry about a meter up along that wall.
 
The joints need redone as they have been wet so long they have turned to sand, when I redo them if I am going to do a chemical damp proof course should I put sbr in the mortar, will it stop the damp proof course creeping?
 
You'll only be able to get at part of the joints to redo them, so putting sbr in the mortar mix won't achieve a lot. Go on ebay, and look for silicone DPC. You drill through the mortar course about 10mm less then the depth, and then pump in the silicone using a sealant gun.
 
Cheers mate, that was the sort of thing that I was planning getting for the damp proof course, so I'll just leave the sbr out of the mortar, ta.
 

DIYnot Local

Staff member

If you need to find a tradesperson to get your job done, please try our local search below, or if you are doing it yourself you can find suppliers local to you.

Select the supplier or trade you require, enter your location to begin your search.


Are you a trade or supplier? You can create your listing free at DIYnot Local

 
Sponsored Links
Back
Top