DPC - builder didn't close hole after injection

happypie

Hi,
Just need some info from expert here about DPC.

I got DPC cream installed in my house about 6-7 months back using this cream: https://www.permagard.co.uk/dpc-damp-proofing-cream-kit

However my builder didn't close the hole which he drilled to inject cream. I plan to close holes now.

Any idea if that DPC protection is broken because hole were open during rain or in general? should i inject DPC cream one more time and then close holes.

thanks.

Davesnave

Most people on this forum will tell you that such 'solutions' to damp problems are temporary at best, and possibly storing up future problems too, so I imagine answers will mainly be along the lines that it won't matter one way or the other.

It might help if you gave some context as to why you apparently needed an injected DPC in the first place, the age of your property and the composition of the walls.

This sort of product is not generally recommended for period property, or necessary, if other aspects affecting the building's fabric are attended to correctly.

Jackmydad

. . . I suspect that it won't matter one way or the other. . .

If you're not happy get the builder back.

FreeBear

Why these chemicals are a waste of money.

This Kiesol cream (and other products) is a water soluble product that is injected under low pressure in to the mortar joints. Modern cement based mortars have a high degree of resistance to moisture penetration, so the spread of the cream is going to be minimal at best. If the wall is damp, the cream will remain soluble and take the path of least resistance - i.e. Out of the hole it was injected in to. Even if the solution does penetrate the mortar joint or brick, the "rising damp" will stop it from drying out and forming that elusive waterproof layer. If it does dry out, at best, you will have a waterproof layer extending a few millimetres from each injection site.


Damp walls usually have an underlying cause - This will be one or more of the following:

• Leaking gutters or downpipes.
• Elevated ground level breaching an existing DPC.
• Debris within a cavity breaching the DPC internally.
• A leaking pipe.
• A cold bridge with high internal humidity.

happypie

sorry i should have mentioned its rising damp.

my house is 100 years old with solid walls.
there was excessive rising damp issue identified in survey when i purchased it last year. then i got rentokil company to do 'free' survey and they also identified rising damp and suggested DPC solution.
in order to save money i didn't go with rentokil for solution and asked my builder to do same.

stuart45

The problem with many surveys is that they call any low level dampness rising damp, and want to inject the walls. Just using a damp meter isn't enough to diagnose the problem. Condensation will often form at the base of a wall. A 100 year old house will probably have a DPC already.

ka7e

Water does not defy the law of gravity and bricks are not incredibly porous - if they were, driving rain would permeate all brick walls. Rentokil diagnoses "rising damp" because they sell the products that allegedly fix it .

FreeBear

happypie wrote: »

sorry i should have mentioned its rising damp.

my house is 100 years old with solid walls.

https://www.architectsjournal.co.uk/home/-rising-damp-is-a-myth-says-former-rics-chief/5204095.article

Well worth a read of this web site so that you can avoid some of the more outlandish "cures" - https://www.heritage-house.org/damp-and-condensation/the-fraud-of-rising-damp.html

On a Victorian property, I would expect to see a row of slate, a course of engineering bricks, or a black line of bitumastic close to the ground level - Any one of these would be a DPC, and would not fail.

Now that you have had holes drilled in the (solid) walls, get them plugged with a pure lime mortar (no cement added). You've wasted money on having chemicals squirted into the walls, but hopefully, you haven't been conned in to having waterproof plaster slapped on the walls internally.

One more point to add - Please don't use gypsum (Multifinish and similar) plaster on the walls. Lime plaster is the best stuff to use on solid brick walls. Antibacterial, very forgiving with condensation, and is in keeping with the age of the property.