Injected DPC on internal walls

[brightspark]

Simplest especially for diy is dryzone paste ... high pressure injection is a pita and is risky on a party wall.

Drybase over before rendering

you dont use high pressure injection now you use damp proof jelly from a standard caulk gun by hand https://www.toolstation.com/dryzone-dpc-cream/p83738

 

[mtt.tr]

I haven't seen any places that needed injection dpc, preferable option is to sort the underlying issue

 

[Welderpaul]

Concrete oversite or suspended timber?

Suspended timber floor

 

[weldingnovice]

Is the underfloor void clean of 5hite?
Are there air bricks? If there are are they clear?

 

[mtt.tr]

Suspended timber floor

As the next comment, is the oversite clear and free breathing?

 

[JOEPRO]

I haven't seen any places that needed injection dpc, preferable option is to sort the underlying issue

How would you do that on an internal party wall with rising damp and no DPC by the sounds of it?

I'll answer my own question.

You can't. Unless internal French drains both sides are an option.
Electro Osmatic.

 

[mtt.tr]

How would you do that on an internal party wall with rising damp and no DPC by the sounds of it?

I'll answer my own question.

You can't. Unless internal French drains both sides are an option.
Electro Osmatic.

Or the oversite is full of ****e or not ventilated


Should we not step back and think, well it was fine up until......

 

[malcolm]

Good answers on this thread. I spend half my time removing tanking. It hides the damp for a few years. The water ingress is often really slow but the walls will slowly become soaking wet.

I would forget any injected DPC. It might theoretically work but in practice it rarely does.

An underfloor under wood will only work if it is vented properly. You want a cross flow of air ideally. The bricks under there should be pointed in lime so they'll dry the wall before damp gets up to the floor.

 

[brightspark]

i must have been lucky then did mine 25 years ago .took a brick out every meter and cleaned the cavity out drilled and injected half the house the other half i took out 2 rows of bricks 3 foot at a time put a proper plastic damp proof membrane in and bricked back up using engineering bricks using waterproofed mortar. sprayed the outside walls with silicone and never had and bother since of either

 

[mike os]

The Dryzone products do seem very popular, I did plenty of yoootoobing and lots of people/companies use it. I can't see which would be the most suitable product (performance-wise) between their rods and the injected paste.

I've not used the rods, they were not available when used to do it

The injection paste is very good if installed correctly

 

[weldingnovice]

Dryzone, tanking etc do work well and will mask the problem.

9 times out of 10 ventilation and/or insulation.