# Forum Home Renovation Waterproofing  Water proofing external stairs/wall

## tomato_brine

Hi 
 I have water penetrating through mortar where my external concrete stairs meet the double brick wall. During heavy rain the water drips through the mortar and runs down the internal wall of the (non-habitable) sub floor space. The mortar between the steps and the wall is visibly deteriorated. 
 I have purchased a tin of masonry water repellent (not a sealant) as well as a tube of mortar gap filler to be caulked. I chose the caulk method rather than attempting to repoint the brickwork as (1) it is a small area, (2) is difficult to get to, being the stairs and (3) I have no experience repointing bricks. I have a few questions about the process and would appreciate any advice. 
 What should go first, the water repellent or the mortar gap filler? Im thinking I should spray the water repellent into the gaps in the mortar, allow to dry and follow with the mortar gap filler. Possibly then go back over with the repellent. The repellent breaths but my assumption is that the gap filler wont. 
 The water repellent instructions state that it should only be applied to dry masonry. How dry is dry? Would two weeks of sunshine be dry enough? 
 Am I compromising quality by using mortar gap filler instead of mixing up my own mortar and having a proper go at repointing? 
 Anything else I should be aware of? 
 Thanks 
 Tom

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## mudbrick

Surely 2 weeks of sunshine would be enough. 
Summer time would be better if you had 6 months to wait.
which filler are you talking about ? I'd say it depends what's letting the water in, if it's the cracks and broken mortar then I would fill those cracks first then seal over the top

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## joynz

Call the tech help number on the repellant container and ask  -  worth checking

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## wspivak

Hi tomato_brine, 
Dry is referring to not recently wet from rain or similar.  2 weeks of sunshine is almost certainly dry enough. 
As for the rest, if you want the repellant to work properly, re-pointing is a must.  Scrape out any existing loose mortar first, then re-point, let dry and finally seal with the repellant.  If you then feel like it, try the gap filler on top, but it's unlikely it will bond with a substrate that has been sealed with a repellant. 
Regards  Waterproofing products, Waterproofing supplies. The WaterStop Shop® - Waterproofing products & supplies

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## tomato_brine

Hi, thanks for replies. The filler is Selleys Mortar Works - Selleys Mortar Works | Selleys Australia. As it seems to be designed specifically for this kind of job I'm not sure why mixing up a mortar and repointing would be a better option. Because it can be caulked into the gaps I was thinking it might be more effective than trying to re-point (?). Grateful for clarification on this. I will call the repellent tech number, thanks.

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## wspivak

Hi tomato_brine, 
Water repellant sealers work by penetrating into the pores of the substrate, in this case mortar.  Gap Filler has no pores (it's probably an acrylic of some description), thus will not accept sealers.

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## tomato_brine

Thanks for advice. I called the tech support area of the water repellent product. They agreed that the repellent would not take to the Mortar Works product. I also emailed Selley's who replied to advise that this product was not the right one for the job (not suitable for areas subject to regular dampness), which is pretty decent of them I think. Apparently they make other products that would be more appropriate for this. Also, they confirmed your post wspivak, it is an acrylic. So anyway, instead of getting another kind if gap filler I will have a crack at the re-pointing. It doesn't look to difficult but if anyone has any tips in relation to repointing bricks in stairs I'd appreciate it. After I've re-pointed I will go over with the water repellent. I asked the tech guy how dry it needed to be and he said it was really important that it be completely dry so I'll start with the re-pointing, which should slow the water down a bit anyway, and then make sure I've had a decent run of dry weather before applying the repellent. Thanks again,

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