HOW SOON CAN I LAY FLOORING AFTER LAYING SCREED?

It can be difficult to know how long to wait before laying flooring on a fresh screed surface. As it depends on the type of screed used, the area covered and the flooring you’d like to lay, there isn’t a definitive answer, unfortunately. However, EasyMix are on hand to help you make that decision.

What is screed?

Screed is a thin, top layer of material which is laid over a concrete subfloor. Traditionally, it’s made up of sharp sand and cement. Industrial screed tends to be a more coarse 6-10mm aggregate, and is used for more heavy-duty applications.

It’s used to cover structural flooring concrete and can be applied to in-situ, solid or precast concrete floor slab. Screed can also be laid over the top of insulating materials, particularly underfloor heating pipes.

Screed is designed to provide a smooth, flat surface that finishing materials, such as floorboards, tiles or carpet, can be laid upon. The level of a floor shouldn’t go much beyond 5mm over a space of 3 metres.

What are the different types of screed?

There are four main types of screed, including:

Bonded screed

Fully bonded to concrete sub-base using a bonding primer or agent. Bonded screed is often applied when thinner screeds are required.

Unbonded screed

Laid over the top of polythene sheeting or a damp proof membrane. This separates the concrete base substrate from the final layer of screed. Unbonded screed is generally applied to older concrete sub-bases.

Floating screed

Laid over a layer of thermal insulation and typically on top of a damp proof membrane, separating the existing concrete sub-base.

Underfloor heating screed

As the name would suggest, this type of screed is laid over the top of underfloor heating pipes as an alternative to other insulating materials. Underfloor heating screed is very similar to floating screed.

What can screed be used for?

Screed is designed to even out a concrete sub-base, ensuring a flat surface with a smooth finish. This allows for carpet and tiles to be laid evenly and with the utmost precision. It can also be used to cover underfloor heating pipes and insulation.

How long does it take for screed to dry?

Depending on the type and thickness, it’ll take at least 24-48 hours to dry. If certain additives are used, the time could be reduced to just 12 hours! For areas which receive heavier foot traffic or if you’re hoping to move or place heavy furniture on it, we recommend leaving it for around 5-7 days. Typically, most screeds will reach full cured strength after approximately 28 days. For the best results, it’s better to wait that long before using a screeded surface.

Can I speed up the screed’s drying process?

In short, yes. Depending on the type of screed, the drying process can be sped up. But this can only really be done if you have optimum drying conditions, or if an additive is used – something underfloor heating screed will benefit from.

Benefits of drying screed faster

• Building work can suffer when drying time takes longer than expected
• Work can be carried out and completed in a timely manner
• Floors can be laid quickly, efficiently and evenly
• Schedule of work can stay on track
• Pressure is relieved for workers in terms of time constraints

How can I be sure the screed floor is ready to be tiled, carpeted or have new laminate floor laid?

The time you wait for screed to properly dry will vary depending on what it is you’re planning to lay on top of it.

Laminate

Typically, you should wait one week per centimetre of screed (thickness) up to 4cm and wait twice as long for every additional centimetre of thickness (up to 6cm). You should wait 4 weeks for every additional centimetre of thickness beyond 6cm.

It will take a considerable amount of time for all moisture to migrate from the bottom to the surface of freshly laid screed. If you have a brand new, freshly laid screed floor, lay a plastic foil down before installing laminate panels. Some laminate panels may have built-in plastic foils or something similar.

Tiles

Screed should be firm enough to walk on before tiling can begin. Depending on thickness, it could be around three days before you’re able to do this and the concrete foundation should be a week old at the very least.

You must ensure that the substrates you’re hoping to tile are both clean and dry before commencing work, with particular attention being paid to movement joints and whether they’re adequately specified.

Lay the tiles, leaving joints of approximately 3mm wide – this allows for grouting and provision for movement. Once the tiles have been laid, grout the joints and fill the perimeter movement joints with silicone.

Carpet

Screed must be as dry as possible before laying carpet down to avoid mould from forming due to rising moisture. Once dry, the screed should then be cleaned and free from contaminants (such as oils, grease or polish for example).

Concrete screeds should be structurally sound, and not contain holes, chips or cracks. If the screed is damaged, you’ll be able to fix it using an approved levelling compound, to be at least 3mm thick.

Floor screed at EasyMix

EasyMix are premier suppliers of floor screed, supplying domestic and commercial clients with concrete products of the highest quality. Our first-rate floor screed service includes its mixing and delivery, enabling you to achieve the perfect finish to your concrete flooring.

The floor screed we provide is available for same or next day delivery, giving you a choice of high-quality, ready mixed or onsite mixed materials. We can even offer two-hour delivery slots once an order has been placed, enabling you to prepare for the arrival of your concrete.

Here at EasyMix, we have a wide range of concrete products and services available for both commercial and domestic customers, including commercial concrete, domestic concrete and concrete pumps.

If you’d like to find out more about the floor screed we provide, get in touch with us today – we operate throughout Hertfordshire  Bedfordshire, Buckinghamshire, Northamptonshire and the surrounding areas.