Surface Preparation and Care of Microcement

The following guidelines are for prime contractors, plasterers, painters, fabricators, architects and clients responsible for preparing/specifying surfaces for microcement and subsequent maintenance. Please read these carefully before you start the preparations.

Can you paint it?

The best way to prepare a surface for SeaStone microcement is to imagine that you are going to paint it. Although microcement is very strong and flexible, it is only as strong and stable as the substrate it is applied to. And like paint, clumps, bumps, holes and movement are likely to transfer to the finished product, which can affect the end result. If you want a smooth finish, resistant to cracks, you need to make sure the substrate is smooth and resistant.

We can help prepare surfaces correctly, but it will be easier and cheaper if this is completed during the initial preparations.

Well consolidated

Surfaces should be properly consolidated. Cracks in the microcement due to unconsolidated surfaces are the responsibility of the contractor who installed the subfloor, not the installer of the microcement.

We can fill cracks and holes created in the surface during the curing process. But further movement in the subfloor creates cracks in the surface.

Although microcement is very hard, it should only be considered as a top coat. It is the responsibility of the subfloor contractor to ensure that the materials used are fit for purpose and properly consolidated.

Connections and expansion joints

Wherever two separate subfloors meet, whether laid at different times or with intentional expansion joints, movement is most likely to occur along the joint. Movement in the subfloors can cause the microcement to crack along the joint.

To avoid cracks in the microcement caused by cold joints, concrete subfloors and screeds should be poured in one go whenever possible, taking into account any expansion joints.

We will insert a bead or threshold to separate the 2 surfaces and microcement on either side up to the bead.

Flat surfaces

Surfaces must be level. Floors that are not level must be leveled with a self-levelling and suitable leveling compound. Leave 4 mm to the height of the finished floor for microcement.

Microcement can be applied to a wide variety of substrates, including concrete, screeds, cement boards, ceramics, plasterboard, plywood, chipboard and MDF.

It is important to remember that surfaces must be flat and level. For that reason we ask that all walls are plastered.

Microcement cannot be applied directly to natural wood which is at risk of warping.

Wooden floorboards must be covered with a suitable cement board. These should be placed flat and against each other.

The boards must be firmly fixed in place (glued and screwed) so that there is no risk of movement. Planks should be laid flat over the entire area. Gaps should be filled with a suitable hard filler, not silicone. Allow sufficient time for the filler to cure before starting work.

Less than 5% moisture content

All surfaces must have a moisture content of less than 5% when we come to install. We can test moisture content on arrival, but please work within manufacturer's recommended lead times for freshly laid surfaces. If the surfaces are not dry when we arrive on site, there will be additional costs and/or construction delays.

Hardness test

We will test concrete floors before laying microcement and will not proceed if they are less than 4 on the hardness scale of MOHs. Floors must be free of dust and excessive cement laitance.

Prepare access and floor

Before we get to work, the area must be completely cleared. There is no access to other work during the time it takes to complete the work (usually 7 days). We would prefer baseboards and kickboards to be removed / omitted before work begins.

Waterproof

There should be no risk of water entering the microcement from outside - eg through open windows/doors or rising damp. There should be no risk of water or other liquids hitting the microcement while we are working in the room as this will stain and will cause further traces for which we will have to charge a fee. Until sealed, the microcement will be very porous so that any water spilled on the surface will stain. Anyone who spills water on the surface or marks it in any way will have to bear the cost of repairs.

Curing times

The microcement is not fully cured until 4 weeks after laying. During this time, be careful not to scratch, drop or drag objects on the floor. The costs of repairing any damage caused will have to be paid by those responsible. After curing, microcement is strong, non-slip and resistant to stains. You can treat it as you would a hard wood floor.

Underfloor heating

Underfloor heating must be commissioned and completed a full cycle (from lowest to highest temperature at intervals as recommended by screed and underfloor heating manufacturers) before arriving on site.

Make sure that the underfloor heating is switched off 48 hours before the start of the work, unless otherwise stated, and keep it switched off during the work.

After applying the microcement, at least 48 hours must elapse before the heating is gradually turned on ( 5 ° C every day).

Keep the water entering the circuits at 25°C for 2 or 3 days. Then gradually increase the water temperature to 45°C and leave it on for several days. Always change the temperature gradually, both at the beginning and at the end of the heating period. Make sure the heating is on within 4 weeks of installing the floor.

Make sure that the relative humidity in the rooms is not too low. Always avoid a build-up of heat caused by rugs and carpets, or the lack of space between the furniture and the floor.

Additional requirements for showers and wet areas

Prior to this, the walls of the shower room up to the shower trays must be plastered. Always do this with a cement-bound stucco. Hard shower trays suitable for vinyl floors must be securely fixed in place to prevent movement. It is the responsibility of the subcontractor installing the tank to ensure that the slope is sufficient to allow the water to flow to the drain. There should be no gaps between shower trays and adjacent floors. Leave about 4mm to the height of the finished microcement floor.

Care for Microcement Surfaces

First 7 days

Like all concrete, it takes 28 days for microcement to fully cure. The first 7 days after laying it is at its softest. During this time, it should only be exposed to light use and foot traffic.

Any heavy work is not recommended, but if it does happen, we recommend covering the floor with a breathable material or covering only while working and removing the protection for most of the time. The surface must dry out and harden. If the airflow is restricted, it may stain and not cure correctly.

Attachment to surfaces after Microcement is installed

Drilling and screwing can be done with drills suitable for the substrate. As it is the sealers that waterproof microcement, any holes must be protected from the ingress of moisture by placing silicone in screw holes or by surrounding fittings and completely with silicone to mount. Care should also be taken not to scratch the sealers or coatings when installing fixtures and fittings.

Don't drag or drop anything

It is not recommended to drag heavy objects over the surface as this may cause damage. To move furniture: It is advisable to lift and support them, never drag them. It is necessary to protect floors with covers or felt from the pressure points of furniture (metal feet, sharp surfaces) or objects with abrasive or heavy contact surfaces.

Despite the lack of thickness, one of the main properties of this material is its high resistance and hardness; some products can even be used in high traffic areas.

Several factors affect the resistance and hardness of microcement, such as the subfloor to which it is applied, the type of microcement chosen and the sealer used.

We can distinguish between two types of resistance:

Mechanical resistance

Microcement, due to its limited thickness, will deform on a strong impact if the underlying support deforms. An example of this is the microcement that is applied to plaster. If the base deforms because it has poor resistance, the microcement will also deform. On a surface such as terrazzo, the resistance will be greater.

Abrasion: This resistance depends on both the type of microcement and the sealer. In general, the wear resistance is comparable to hardwood.

Stain resistance

The chemical resistance depends on the sealer used to protect the product. Our sealers and coatings are among the best in the industry for both hardness and strength.

Both vinegar and lemon juice leave light marks on microcement. These acids attack the surface like marble, but if they are cleaned quickly, they will not stain.

Hydrochloric acid, pure bleach, acetone and ammonia will stain after half an hour, but if the cleaning is done quickly, no stains will remain. If water spots appear within the first 4 weeks of use, please keep the area dry and notify us immediately as stains become permanent if not treated promptly.

Cleaning

To ensure the long and lasting life of our microcements, we recommend the use of water and neutral soap.

The care of microcement is comparable to that of natural wooden parquet. We recommend to avoid permanent wetness or prolonged contact with moisture. Leaving wet carpets and towels on the floor is not recommended, as are leaking pots. The surfaces should also be kept free of stones or grit that could scratch the coating. Avoid bumping and rubbing with hard objects.

Although microcement offers a high chemical resistance, cleaning should be done with neutral soap, never with aggressive or descaling agents. In addition, avoid products such as chlorine, bleach, ammonia, soap and detergents in general, as these can damage the protective film.