Chemical DPC - Without removing render?

[shane2647]

Hi
I live in an old property (roughly 1730 with thick walls, no idea of composition), it has been extended about 25 years ago so some parts are normal brick cavity walls. Entire property is rendered. There are a couple of places where I have had damp and want to put in chemical DPC, last done 1995. Really don't want to strip back render. Is it ok to inject into brick or does it have to be into mortor? Any recommendations on what chemical cream/solution to use greatly appreciated!
Thanks
Shane

[Someone-Else]

You may want to read This

[wes56]

For what they are worth, chemical DPC's are injected into mortar beds.
No fresh DPC injection will work because the render thats covering the DPC will be bridging any old DPC, and will continue to bridge any new DPC.
Without disturbing the render how would you determine where the mortar beds are?
Chemical DPC's appear to sometimes work but it depends on the circumstances.
Without pics of the outside of the building, and the damp areas on the inside, its almost impossible to advise you.

FWIW: a 1730's building would typically be a listed building where no aspect of DPC work could be done without a Conservation Officer's permission.
There are other ways of dealing with damp interiors.

The article user name S-E directed us to is half right and half wrong. Similar to that weird character Peter Ward of Heritage House - some of his stuff is very good and some is rubbish.

[arco_iris]

I live in an old property (roughly 1730 with thick walls, no idea of composition)

.....

chemical DPC, last done 1995

.......

Entire property is rendered.

Combining these three things is kiss of death.

1995 chemical DPC is contributing to the problem, probably too late, don't make matters worse.

Render is compounding the problem.

The answer, and even then only partial, you don't want to hear! Chemical dpc has already b*gg*r*d it, "they" didn't understand in 1995 (more people do now).