Would replacing old mortar for new prevent water from seeping through brickwork?

I have included photographs just in case this is a special case:

Corner View 1 Corner View 2 Corner View 3 Drain View 1 Drain View 2

2 Answers 2


It wouldn't hurt. looks like a lot of that mortar is just missing with holes and cracks. Looks like rain and a bit of wind could drive rain right through it.

That said, it looks like the brick is also damages. Brick with a damaged face will also take in water like a sponge. They do make spray-on brick sealant. I can't say it it works or not, but might be something to look into.

  • Agree with "DA01" about "It wouldn't hurt". The secret to a good & successful repointing job is proper preparation. I have used a "brick sealant" product once, after repointing a two story exterior side (flank) wall on a house. I can't say if it worked (or was really needed), but the customer wanted it applied. After completing the work, the customer never called back to say water was coming in (as it had before).
    – Mike Perry
    Commented Jul 25, 2011 at 0:03

just looks like the mortar used was not mixed properly- more sand ratio (this is a common problem in British builds form the 1900's)-- and over the years it started to crumble out. In comparison- the bricks are in very good condition compared to the way the mortar crumbled out.. The bricks look solid- I suspect the breaking occurred when you removed the plaster?

Agreed with @Mike Perry - To solve the problem you will need to do it properly- Get the whole palster off, check the state of all the mortar- re point them properly (using sealants..etc) and maybe re-plaster or using some new techniques.. eg insulating it with poly blocks, create will help in heating costs and protects old walls very well. In UK/EU you can go to a .gov site and search for subsidies as the governments can fund up to %50 for insulation and some countries even 100% for green energy solutions..

  • the real problem with brickwork mortars used back in the "old" day's in the UK = They were lime based. Plus, all mortars have a "shelf-life", before they really need replacing or repairing...
    – Mike Perry
    Commented Jul 26, 2011 at 1:13
  • Yea lime too.. but when concrete came into use there was allot of experimenting and incorrect mixtures used.. i have seen were a building is dissintigrating on the top but OK on the bottom because of this exact problem.. never a nice thing to see.
    – Piotr Kula
    Commented Jul 26, 2011 at 7:55
  • When do you need to use sealants and when is regular mortar with plaster on top enough? And what about this particular question made you say he needed to use a sealant? Just trying to learn more about it.
    – Yitzchak
    Commented Jul 26, 2011 at 15:13
  • I never used any sealants to be honest. I suspect that if you seal the wall before applying plaster it would minimize the weather affect? so instead off 100years it will last 150years? Giving that you mix the mortar to the correct ratios. I would say its more important what you put on top of the wall- good plaster or good insulation.
    – Piotr Kula
    Commented Jul 26, 2011 at 15:42
  • @Yitzchak, I can't speak for others here, but I only spoke about "sealants" because of there mention in DA01's answer. Personally, without seeing the actual situation in person it's a little hard for me to say which method ("repoint & seal" or "repoint & render") would be best.
    – Mike Perry
    Commented Jul 26, 2011 at 15:44

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