Using Dryzone

[dave]

A followup to my ealier post "Salt coming out of external Brickwork".

I've not used Dryzone (or equiv) chemicals before, so just to ask about their application.

I see from the adverts they provide a applicator and long tube - but does the material "set" in the tube if you stop squeezing the trigger

- or does it take a while?

Another reason I ask is that I learned the hard way using that expanding foam stuff. There was me thinking I could use it a few times

- but (as folk here will know), it sets in the tube - and is impossible to clean out again.

Dryzone is a bit expensive so just like to know what to expect before starting.

Thanks

[chudford]

I used Dryzone to damp proof my son's house.

It was a very easy job but requires a high power masonary drill to drill the many holes.

You just drill into the mortar joints between the bricks and squeeze in the Dryzone.

The Dryzone is a creamy consistency and does not set in the applicator.

It permeates into the mortar and reacts with the water forming a damp proof layer in the mortar.

I did this over 3 years ago and it has cured the damp problem in his Victorian terraced house.

You can clearly see where the damp layer of bricks ends and the now dry layer starts.

Expensive but very efficient.

[dave]

Great info - thanks - just what I neeed to know.

Did you drill the holes into the damp course of bricks itself (we have

2 layers of blue brick which is (supposed to be) the damp course. I guess below it would be best but don't know if I can get to that layer here.

[chudford]

My son's house had no damp course bricks so cannot really help.

If the blue bricks are only just below the floor joist level then you should try to inject below the blue bricks, if not then above would be OK.

The dryzone spreads up and down through the mortar

[Tabby]

I wonder how much sense it makes to inject a chemical 'dpc' when the OP already has a blue brick dpc, and IIRC it tested dry. The signs point far more to condensation.

NT

[dave]

The bricks did indeed test dry, but not the mortar between them. Got readings on every mortar "line".