Post-construction residue cleaner D-2B CTS Chemistry

An acidic product (pH approx. 2) for mortar residues, cement laitance and marks left by building work. 2-6 m² per litre. It must not contact metal, galvanised or painted coatings, or render.

Surface

Block paving

The surface the manufacturer intends this preparation for.

Block paving

D-2B is an acidic product for post-construction soiling: mortar residues, cement laitance and the marks left by bricklaying and rendering.

The manufacturer gives a list of prohibitions as important here as the intended use: the product must not contact metal surfaces, galvanised or painted coatings, render, or any other material that absorbs water.

The dilution depends on the scale of the problem: heavy soiling 1:1, extreme soiling undiluted. Coverage 2-6 m² per litre, pH approx. 2.

The usual reason a sealing job fails is not the product but the substrate. A sealer will not bond to a surface with grease, lime efflorescence or an old coating on it.

  1. Wash the paving. Lift oil stains with a degreasing cleaner - water alone, even under pressure, will not shift them.
  2. Remove lime efflorescence with a product made for it, not with hydrochloric acid from the builders' merchant.
  3. Make good the joints and let them set. Sealer applied over an empty joint runs straight into the sub-base.
  4. Wait until the paving is dry all the way through, not just on top. Moisture trapped under the film can bloom it white.
  5. Check the forecast. Rain within a day of application will wash off a fresh coat.

New paving has to season first. Manufacturers state that period on the data sheet - usually around 28 days from the date the block was made. The figure for each product is under "Technical data".

Before sealing the whole area, test on a patch hidden by a planter or in a corner of the patio. The same product can read differently on two batches of the same material, and on a surface with old coating left on it, it will not bond at all.

Coverage
2-6 m²/l
Coats
1
Application method
hand sprayer, brush (stiff), pressure washer
Dilution
Heavy soiling 1:1; extreme soiling - use undiluted.
Where to use
indoors, outdoors
Form
acidic solution
Density
approx. 1 kg/dm³
pH
approx. 2
Must not contact
metals, galvanised and painted coatings, render and other absorbent materials
Will the sealer change the colour of my paving?

That depends on the finish given in the technical data. An invisible product leaves the colour alone, a wet-look version deepens it permanently, and a colour sealer gives it a new shade. Each product's finish is listed under "Technical data".

How do I know when to seal again?

By how the water behaves. While it still beads on the surface, the treatment is working. Once water starts soaking in and dark patches return after rain, the protection has worn out. We do not quote a number of years, because it depends on traffic, sun and whether the drive is salted in winter.

Can I apply sealer to wet paving?

No. Water occupies the pores the product is meant to enter, and stays trapped under the film. The result is often a milky bloom that cannot be removed without stripping the coat. The exceptions - products that allow slight surface dampness - say so in their technical data.

How much do I need to buy?

Use the calculator under the product description: it takes the manufacturer's coverage figure, the number of coats and the absorbency of the substrate, and turns them into pack sizes. On older, thirstier paving, work to the lower end of the coverage range.

Will sealing make the paving slippery?

Penetrating products form no film on the surface and do not change its grip. Where a manufacturer says something about slipperiness, we quote it in the technical data. If the surface is already slippery, the right product is an anti-slip treatment, not a sealer.

How do I turn a dilution ratio into a quantity?

A 1:4 dilution means one part product to four parts water - a litre of concentrate gives five litres of working solution. Where the ratio is given in ml per litre of water (the C range), work the other way: 50 ml per litre means 20 litres of solution from one litre of concentrate.

D-2B or D-2W?

The same acidic chemistry, different uses on the data sheet. D-2B targets post-construction soiling - mortar and cement laitance. D-2W targets lime and carbonate efflorescence, which appears later, in use.

Will it harm the joints and edgings?

An acidic product acts on the cement binder, and the manufacturer rules out contact with render and absorbent materials. Metal edgings and painted elements have to be masked.

The technical sheet and safety data sheet will be available after approval.

Coverage calculator

Enter the area and how absorbent the substrate is. We work out the litres and the packs.

Depending on how heavily soiled the surface is and on its texture.

Substrate absorbency

Calculated at 4 m² per litre.

Example for 45 m²

11.3L

  • 2 × 5 l405,90 zł
  • 2 × 1 l98,40 zł

Enter your own area to calculate for your job.

Looking for another surface?

Go directly to the right category. We do not imply compatibility across materials.