Component A
Component A behind a drained cavity, with a cementitious waterproof coat on the face. Foam is the second line, not the first.
See specificationBasements
Basement damp and seepage, treated from inside
You cannot dig out a finished basement. Foam closes the cold joint, the tie holes and the crack — from the dry side.
What goes wrong on site
Three failures, in the order they appear
- 01
Seepage on the negative side, where no membrane can be applied.
- 02
Damp that becomes mould behind the lining, out of sight.
- 03
No excavation possible: the building is finished and occupied.
Why one-component foam, and not something else
Three properties, no chemistry
- Mobility: a can and a gun reach a joint that a panel, a board or a truck cannot.
- Irregular geometry: it expands to the shape of the void, including penetrations.
- Closed cell: air barrier and moisture barrier in one pass, without a second trade.
How it is done, and what to hold
The four numbers this job lives on
| Step | What to hold |
|---|---|
| Surface | Joint and cracks opened and cleaned, loose render removed, active running water stopped first. |
| Fill volume | One third of the joint depth. The foam expands to fill; filling it to the top bends frames and wastes material. |
| Passes | Two passes of 30 mm at most. A single thick pass traps heat and collapses in the core. |
| Trim | Cut after the window on the parameter card. Never pull or press uncured foam. |
| Cover | PU is not UV-stable. Any exposed face gets sealant, render or a trim within 48 hours. |
Typical guidance. The parameter card for your grade carries the tolerances your operators work to.
Common failures
Three ways this job goes wrong
- Foaming over a wet wall: the foam skins, the water stays behind it.
- Treating foam as a waterproofing membrane. It is not one.
- Sealing the crack without relieving the pressure — it finds another line.
What to tell your customer
Three sentences you can copy into a quotation, a WhatsApp message or a site meeting. Your competitors' websites talk about themselves; this block is for you to talk about the job.
„We stop the water first, then foam. Foam behind a wet wall does nothing.“
„The cold joint and the tie holes are the two places water always enters.“
„This is a drained-cavity detail, not a paint-on coating.“
Send the drawing or the photo — we will reply with the parameters.
Technology brand
Tell us the joint, the substrate and the season
- 1 tonne minimum, five 200 L drums
- SDS, COA and Form E with every shipment
- We reply within 24 hours, Monday to Saturday.