We have a damp external wall constructed from breeze blocks. The floor is also damp, which I am going to treat with a liquid DPM. I plan to tank the walls too, but want to know if I should treat the breeze block walls with a chemical DPC first?
Can you do that with breeze blocks? The lower blocks are wet, not the mortar course but the blocks themselves!
To cut a long story short, we are certain it's rising damp. To cut an even longer story short there isn't much we're able to do externally, although I do plan to dig an open french drain to eliminate as much soil as possible from being in contact with the walls.
However, for this question, I want to focus on whether I can actually inject a DPC or use dry rods in the breeze blocks.
Update: I believe the blocks to be thermalite, but not 100% ceertain.
Are you a tradesperson and able to answer this question?
Hello , firstly are the blocks Thermalite or concrete ?
if the lower blocks are concrete then you can use Dryrod Damp-Proofing Rods from Safeguard which will separate the lower blocks from the above
creating the DPC if there is not one .
Answered29 April 2022
1
Anonymous user
Yes a liquid damp proofing product from most building merchants for masonry works will be suitable. Bitumen based is what you’re looking for. Kind regards south west pointing
Answered29 April 2022
0
Anonymous user
You will need to prepare both internally and externally before injecting your damp proofing cream. Start by removing any skirting boards, architraves, as well as disconnecting any radiators. You will want to expose the brickwork to the required level before starting injecting the DPC.
If you are suffering from rising damp then damp will have left tidemarks and other visible damp damage on the plaster. It is important to remove this contaminated plaster before injecting a DPC. Hack off the plaster to a height of no less than a metre.
In some rare instances, depending on the conditions, the water may have been wicked up higher than one metre so you should consider removing plaster at least 300mm above the highest visible sign of damp/ hydroscopic salts. It’s also worth pointing out that rising damp will not necessarily rise uniformly to the same level across all parts of a wall so adjust the amount of plaster to be removed accordingly without ever slipping below one metre.
