Mapei waiting times: when to tile, grout or walk on it

How long before tiling over Mapelastic?

It depends which Mapelastic is on the floor. Mapelastic Easy says to wait at least 5 days for curing before laying ceramic tiles. Mapelastic AquaDefense is the quick one: 3-4 hours in the table and 4 hours after the second coat in the body of the same sheet, so work to the longer figure. Mapelastic Foundation gives approximately 6 hours between coats and no wait before tiling.

The usual mistake is a tiler arriving the next morning because the Easy looks dry. Looking dry is not the test, since the sheet calls those 5 days curing. It adds that the wait can be longer in cold conditions and may be reduced in good weather, with no figure for either, so 5 days is the number to plan on.

On an open terrace in the masika or vuli rains, the first day matters most. Easy and Foundation both say to protect the coat from rain for the first 24 hours.

Mapelastic Smart is not in the table because its current data sheet is not yet on our file. Check the current sheet before planning around a number.

How long before grouting and walking on tile adhesive?

On floors, 24 hours for both grouting and foot traffic. On walls, grout after 4 to 8 hours. All four cementitious adhesives print the same figures, under a heading of +23°C and 50% relative humidity.

The wall range is not a free choice. Mapeset and Adesilex P7 tie it to absorbency, so a dense tile on a dense background belongs at the long end. Grout too soon and the pressure of the float can shift a tile that has not yet gripped.

Foot traffic at 24 hours means someone walking with care. It does not mean a loaded wheelbarrow or stacked boxes of tile. Ready for use is 14 days, and Keraflex Maxi S1 adds that swimming pools and basins may be filled 21 days after application.

None of these is a fast adhesive. The Mapeset, Kerabond T and Keraflex Maxi S1 sheets each say not to use the product where a floor must go back into use quickly. If a shop or kitchen cannot close for a day, settle that before the tiles are bought.

How long before a grouted floor can be used?

Light foot traffic at 24 hours for both grouts, then 3 days to ready for use for Keracolor FF and 4 days for Kerapoxy. Water-holding work takes longer: 7 days for Keracolor FF in tanks and swimming pools, 10 days for Kerapoxy in basins and swimming pools.

Keracolor FF has one short wait that catches people out. After filling the joints, the sheet gives 10-20 minutes before finishing. Clean too early and the sponge drags grout out of the joint. Leave it too long on a hot slab and it becomes hard work to clean. Never loosen a stiffening mix with water: the sheet forbids adding water to a mixture that is beginning to set.

Kerapoxy says plainly that its times may vary according to the temperature. Its foot traffic time is given at +20°C and its 4 days at +23°C. It also has the narrower working range, from +12°C to +30°C, so an exposed slab in the afternoon sun can be outside it.

If a sealer follows, UltraCare Stain Protector W Plus needs 2 hours. Its sheet says not to apply it in direct sunlight or if rain is forecast within the next few hours.

How long before tiling or flooring over self-levelling compound?

A minimum of 3 hours before ceramic tiles and light foot traffic, on both compounds. They differ only at the wood line: 48 hours for Ultraplan Eco 20, whose sheet is titled Ultraplan EC20, and 24 hours for Ultraplan Contract, which must also be at least 3 mm thick under wood.

Every figure is a minimum at +23°C, and both sheets say the time can vary with room temperature and humidity. The EC20 sheet adds the thickness of the levelling. So a 10 mm pour in a closed, humid room is not the same job as a 2 mm skim with the windows open, even though the table gives one number for both.

Heat cuts the other way. Pot life is only 20-30 minutes on the EC20 sheet, which says not to attempt large areas above +30°C and to avoid exterior work in direct sunlight. On a hot day in Dar es Salaam, mix smaller batches and pour early. Neither compound is for exterior use.

How long should a primer dry before the next coat?

Primer G takes 30 minutes on concrete and 30-60 minutes on gypsum before the levelling compound or adhesive goes on. The two epoxy-based primers take far longer and, more to the point, they also have a deadline.

Primer SN needs a minimum of 12 hours, then a maximum of 48 hours if it has no quartz sand on top. With a dry-shake finish of quartz sand there is no maximum limit, provided the surface is dry with no dust. If the floor layer might not turn up on time, that decides how you finish the primer.

Triblock P has two windows. Its second coat follows the first after 4-6 hours. The floor or smoothing compound then goes on from a minimum of 24 hours up to a maximum of 7 days.

A primer laid before a long holiday and forgotten is how these windows get missed. The sheets give no remedy in these figures, so write the dates on the wall in chalk.

How do heat and humidity change these times?

Heat shortens them and humidity usually lengthens them, but almost no sheet gives you a figure for either. The membrane, tile adhesive, grout, levelling and primer times above come with no hot-weather value, so we will not invent one.

Dar es Salaam is not the laboratory. A published study gives monthly relative humidity there as 77 to 86% and the annual mean air temperature as about 26°C, against the 50% and +23°C in most sheet headings.

The table shows what Mapei does print, all for resin products. In cement products, heat works against you in a different way: all four adhesive sheets warn that strong sun, drying wind or high temperature can cut open time to a few minutes. A cement mix that loses its water to a hot slab has dried without curing properly, so a warm day is no reason to grout early.

Humidity is slower to show. Water-based products such as Primer G dry by losing water to the air, and humid air takes it up more slowly. Mapefloor FC 200 ME goes further and sets a limit: the air's relative humidity should not be greater than 75%. Measure on the day.

Do not add these rows into one programme for a job. The sheets give a minimum for each step at their own stated conditions, and each product page has the full data sheet as a PDF.