In a rubble stone wall, water does not pass through the stone itself but through the mortar joints and the voids inside the wall. We inject the gel exactly into these paths, through packers placed in the mortar joints. This forms a layer in the middle of the wall thickness that cuts the water paths. The façade is not touched and the wall keeps breathing.
Stone wall gel injection is a way of stopping water that passes through the core of rubble stone and mixed masonry walls. Packers are placed not in the stone but in the mortar joints, on a 30–50 cm grid and to half the wall thickness. Open joints are first closed with R101, then Dryvatec G101 acrylate gel is injected at low pressure from the bottom up. The gel spreads through the network of voids and forms a water-stopping layer in the middle of the wall. It does not form a film on the surface, so the wall breathes.
The rubble stone wall we often see in the basements of old buildings, village houses, retaining walls and historic structures is in fact a core built up from two faces, with stone and mortar packed in between. The stone itself lets very little water through. The water finds its way through mortar joints that turn to sand over time and through the interconnected voids inside the core.
The result is dampness on the inner face, plaster that blisters and falls off, white salt efflorescence and mortar that runs out like flour. The outer face is buried in the ground, or is a listed façade, so it cannot be reached. Sealing the inner face with a cement-based plaster often makes the problem worse: the water looks for somewhere to go, comes out at the edge of the plaster or at higher levels, and breaks down the stone faster.
Gel injection works with the nature of the wall. Acrylate gel, with a flow close to that of water, enters through the mortar joints and spreads through the network of voids in the core, and stays flexible once cured. The impermeable layer forms inside the wall; since there is no film on the surface, the wall keeps breathing. That is why it is an internal method for historic buildings and for places where the outer face cannot be reached.
Not all dampness in a stone wall is the same. The cases below are where gel injection is most useful.
A rubble stone wall in an old building basement, with soil on the outside, gets wet after rain or stays permanently damp.
There is no permission to work on the façade, or the outer face is to be protected. The work is done from inside, without damaging the fabric.
White salt crust, blistering plaster and crumbling mortar on the inner face mean the water is passing through the wall.
Stone retaining walls with soil behind them that let water into the spaces at the lower level.
Dampness with no water pressure, seen only at the bottom of the wall, is usually rising damp. There the right solution is not gel but the D101 DampStop horizontal barrier.
In the D-08 detail the soil side is on the left and the inside of the structure on the right. Note that the gel forms in the middle of the wall, in the mortar and the network of voids. Click the image to enlarge it.
A wall built up from two faces, with stone and mortar packed in between. Water passes through the mortar joints and internal voids.
In the mortar joint, not the stone; 30–50 cm grid, depth half the wall thickness.
A layer filling the network of voids in the middle of the thickness. It does not form a curtain on the soil side.
R101 repair on the inner face, then optionally W101 HydroFix or N102 Crystal 2K.
The drawings are the application steps of the D-08 detail. In a stone wall most of the effort goes into the preparation before injection.
Deteriorated plaster, loose mortar and salt crust are removed. Once the wall is bare, the pattern of the joints and the lines where water enters become visible, and are marked.
Holes are drilled not in the stone but in the mortar joints, on a 30–50 cm staggered grid and to half the wall thickness. Joints that have emptied out are first closed with R101, then the packers are tightened.
G101 gel is injected at low pressure with the two-component pump, starting from the bottom row. When gel appears at the neighbouring packer, we move to the row above. The gel aims to cut the water paths in the middle of the core.
Once the gel has cured, the packers are removed and the holes are filled with R101 Repair Mortar.
Open joints and defects on the surface are repaired with R101. The wall ends up with a flat, sound surface.
The wall is plastered from floor to ceiling with W101 HydroFix damp-control render, so the wall keeps breathing. If the water load is high, N102 Crystal 2K can be chosen instead.
The application dimensions are specific to this method; the material values come from the Dryvatec G101 technical data sheet.
| Item | Value |
|---|---|
| Packer position | Mortar joint (not the stone) |
| Packer grid | 30–50 cm staggered |
| Hole depth | Half the wall thickness |
| Preparation | Open joints closed with R101 |
| Property | Value |
|---|---|
| Viscosity | 5–30 mPa·s, close to water |
| Crack width it can enter | 0.05 mm – 4 mm |
| Mixing | Two mixes, 1 : 1 by volume, with a two-component pump |
| Reaction (gel) time | About 35 seconds to 24 minutes, set by the G202 ratio |
| Pump pressure | 5–100 bar; always start at the lowest workable pressure |
| Minimum application temperature | +2 °C |
| Density / pH | 1.15–1.20 g/cm³ / 6–7.5 |
| Flammability | Non-flammable; water-based |
| G202 ratio | Gel time |
|---|---|
| 0.15% | ≈ 11 minutes |
| 0.5% | ≈ 3.5 minutes |
| 1% | ≈ 1.7 minutes |
| 2% | ≈ 1 minute |
| 4% | ≈ 35 seconds |
| Mix | Liquid | Where |
|---|---|---|
| A — Standard | 20 kg water | Static cracks, porous concrete, the body of a stone wall |
| B — Fully flexible | 20 kg G102 | Moving cracks and expansion joints |
| C — Semi-flexible | 10 kg G102 + 10 kg water | Cases in between; chosen after a trial on site |
Reaction times are laboratory values. On site, cold water lengthens them and hot weather shortens them, so every job starts with a cup test. The G201 / G202 catalyst is part of the four-component system.
A job in the rubble stone basement wall of an old building. The packers were placed not in the stones but in the mortar joints between them. The photo is from our own site.
Unlike curtain injection, the gel stays inside the wall. The water keeps reaching the outer face of the wall but cannot get through the core.
One wall may be tight inside and the next one full of voids. That is why we start with a trial area and write the quantity in the site record.
If the wall is bulging, separating or at risk of collapse, structural strengthening is discussed first. Injection does not provide load-bearing capacity.
After injection we do not close the inner face with a dense cement-based plaster. W101 HydroFix lets the wall release vapour to the outside.
Acrylate gel is not a single method; how it is applied depends on where the water comes from. The highlighted row is the subject of this page.
| What you see | The right application |
|---|---|
| A large part of a buried RC basement wall is wet; water comes through cracks and cold joints | Curtain injection behind the wall (D-06) |
| Water comes in through the joint between two blocks; the old sealant or tape has failed | Expansion joint gel injection (D-07) |
| Water and salts come through the body of a rubble stone or masonry wall; the outside face cannot be reached | Stone wall body injection (D-08) (this page) |
| Water rises from under the slab, through cracks and joints in the floor concrete | Under-slab and foundation gel injection |
| The lower part of a brick or stone wall is damp, there is no water pressure, paint and plaster blister from the bottom | Not gel: D101 DampStop rising damp injection |
| A single crack or service penetration leaks at one spot | Crack injection (PU or acrylate gel) |
In a stone wall, the preparation and the surface that hold the gel in the wall are as important as the gel. All the products we use are from our own brand, Dryvatec; on the inner face we also use W101 HydroFix damp-control render.
Because we make the material ourselves, whatever we run into on site goes straight back into the formula and the application instructions. The section drawing and steps on this page are part of the Dryvatec application detail set.
The core material of the system. A four-component acrylate gel almost as thin as water (5–30 mPa·s); it gets into hairline cracks down to 0.05 mm wide and stays flexible once cured.
Product page
An acrylic polymer that makes the gel more flexible and improves its bond to concrete. In moving cracks and joints it replaces some or all of the water in the mix.
Product page
Repair mortar that closes the holes after the packers come out, as well as opened joints and broken surfaces.
Product page
A two-component crystalline waterproofing applied to the inside face. Optional after injection, as a second line of protection and a clean finished surface.
Product pageOur YouTube channel has real site footage of our injection work.
We work with teams based in Istanbul and Izmir; on stone wall jobs we have also had sites in other provinces such as Ağrı and Malatya.
From our Maltepe office to every district on the European and Asian sides.
From our Konak office to every district of Izmir and the wider Aegean.
For basement walls buried in the ground: a gel barrier behind the wall, with no excavation.
Application detailThe moving joint between two blocks sealed from inside with flexible gel, both within the joint and behind it.
Application detailWhen the water comes up from under the basement slab: a gel layer beneath the slab, without breaking it out.
Application detailSend us a few photos of the wall, close up and from a distance, through the survey request form. From photos we can largely tell whether the water is coming through the body of the wall or from the foot of it; the rest we can see at the survey.
