Popular: Sikaflex · waterproofing · grout · data sheets
Joining fresh concrete, screeds, toppings, renders or repair mortar to existing hardened concrete, for slab thickening, extensions, toppings and repairs. The joint is only as good as the surface preparation and the bond coat.
General guidance based on the manufacturer data sheets. Site conditions differ: confirm the system with MCT before you start. Where we do not name a product, ask us and we will confirm the right one.
If the new concrete must carry load together with the old (slab thickening, jackets, extensions), an engineer must design it, including any dowels; structural bonding needs an engineer's design calculations (Sikadur-32 LP p.3).
Remove laitance, oil, coatings and loose material and roughen until the aggregate shows, e.g. by shot blasting, sandblasting or high-pressure water jetting (Emaco S 488 p.2). For epoxy bonding the concrete must be at least 3–6 weeks old and dry or matt damp, with no standing water (Sikadur-32 LP p.3).
Sikadur-32 LP bonds fresh to hardened concrete (p.1). Brush it well in on matt damp concrete, then place the new concrete while the coat is still tacky; if it turns glossy, apply another coat (Sikadur-32 LP p.3, p.4). Application +20 °C to +40 °C (p.1). For experienced professionals only (p.1).
As a structural bonding agent and adhesive for: Concrete elements (including bonding fresh to hardened concrete), Hard natural stone, Ceramics, fibre-cement, Mortar, Bricks, Masonry, Render, Steel, Iron, Aluminium, Wood. (TDS p.1)
Sikadur ADH 1414 bonds renderings, granolithic toppings and concrete to concrete, and tolerates some moisture (Sikadur ADH 1414 p.1). Leave it to stand before overcoating, typically 60 minutes at 25 °C or 45 minutes at 40 °C (p.2).
Sikadur® ADH 1414 may be applied to clean, sound and durable surfaces, i.e. (TDS p.1,2)
For screeds, renders and repair mortars, mix latex 1:1 with water, then with fresh cement and fine sand to a brushable slurry; brush it onto the pre-wetted surface and apply the mortar wet on wet (SikaLatex-200 SBR PK p.2; SikaLatex PK p.2). SikaBond DV PK is also used as bonding slurry for fresh to old concrete (SikaBond DV PK p.1).
SikaLatex®-200 SBR PK is used as bonding agent and site-mix mortar admixture for the following applications: Thin layer patching mortars, Renders, Floor screeds, Concrete repair mortars, Abrasion resistant linings, Tile fixing mortars. (TDS p.1,2)
SikaLatex® PK is used as bonding agent and sitemix mortar admixture for the following applications: Grouts and screeds, Patch repair mortars, Mansonry mortars, Renders, Tile adhesives. (TDS p.1)
SikaBond® DV is used as bonding agent and sitemix mortar admixture for the following applications: Thin layer patching mortars, Renders, Floor screeds, Concrete repair mortars, Abrasion resistant linings, Tile fixing mortars. (TDS p.1)
In concrete repairs, MonoTop-610 is the bonding primer: apply it to the pre-wetted concrete and place the repair mortar wet on wet (MonoTop-610 p.1, p.2).
Bonding primer as part of a concrete repair system Reinforcement corrosion protection as part of a concrete repair system (TDS p.1)
Cure the new screed, render or concrete with a fine water spray and polythene, or a curing membrane; poor curing can crack it (Sikadur ADH 1414 p.2). In heat, cure well to prevent plastic and drying shrinkage (SikaLatex-200 SBR PK p.2). Carry existing expansion joints through the new layer (Sikadur ADH 1414 p.2).
A starting point for a site proposal. Quantities, prices and the final specification follow a site visit or photos.
| Step | Product | Pack | Source |
|---|---|---|---|
| 3. Structural epoxy bond for fresh concrete | Sikadur-32 LP (professionals) | — | TDS p.1 · March 2025, Version 02.01 |
| 4. Epoxy bond for renders, toppings and screeds | Sikadur ADH 1414 | Sikadur® ADH 1414 is available in 2 litre kits containing the base resin and | TDS p.1,2 · September 2024, Version 02.01 |
| 5. Cementitious bonding slurry | SikaLatex-200 SBR PK | — | TDS p.1,2 · February 2026, Version 03.01 |
| 5. Cementitious bonding slurry | SikaLatex PK | 05 ltr jerry can 20 ltr plastic can 200 ltr drum 1000 ltr IBC Bulk supply in tanker is… | TDS p.1 · June 2025, Version 02.01 |
| 5. Cementitious bonding slurry | SikaBond DV PK | 05 ltr jerry can | TDS p.1 · June 2025, Version 02.01 |
| 6. Bond coat for repair mortars | Sika MonoTop-610 (professionals) | — | TDS p.1 · May 2021, Version 01.01 |
Ask us: it depends on site conditions. For structural joints between fresh and hardened concrete, Sikadur-32 LP is the TDS-listed structural bonding agent (Sikadur-32 LP p.1).
Place concrete while Sikadur-32 LP is still tacky; if it turns glossy, apply another coat (p.4). The open time is about 120 to 270 minutes depending on temperature (Sikadur-32 LP p.3).
No. Never use latex alone or a latex-water mix as a bonding bridge; always add cement and sand (SikaLatex PK p.2; SikaLatex-200 SBR PK p.2).
Sikadur-32 LP is applied at +20 °C to +40 °C (Sikadur-32 LP p.1). Sikadur ADH 1414 cures slowly in cold weather; 7–10 °C is the lowest for vertical rendering (Sikadur ADH 1414 p.2).
At least 3–6 weeks for Sikadur-32 LP (Sikadur-32 LP p.3).
Steps and product facts are taken from the manufacturer data sheets (page cited). Products are named only where the data sheet confirms the use; quantities follow a site visit or photos. General guidance: check the data sheet or ask us before you start.