Floor screeding
A finished floor is only ever as flat as the layer beneath it. Where a slab is uneven, too low or simply not smooth enough for the surface going on top, a screed is laid to bring it to a true, level base. Get the screed right and the resin floor, tiles or covering that follows sits flat and lasts; get it wrong and every dip, fall and high spot telegraphs through the finish.
Surface Specialists arranges floor screeding as part of preparing a floor for a new surface. We assess the slab, specify the right screed for the depth and the finish going on and arrange installation by experienced specialist contractors, so the base is flat, sound and ready. You deal with one point of contact throughout. This page explains what floor screeding is, the types of screed, how thick a screed needs to be and how long it takes to dry.
What is floor screeding?
Floor screeding is the laying of a levelling layer over a concrete slab or subfloor to bring it up to the right height and provide a smooth, sound surface for the final floor. The screed is not the structural slab and it is not the finished floor; it is the layer in between that makes the floor flat and ready to take a covering, whether that is resin, tiles, vinyl or a coating.
A screed can be a traditional sand and cement mix or a modern pumped liquid screed, and it can range from a thin levelling layer to a thicker build-up where the floor has to come up some way. The right screed depends on how much height is needed, the timescale and what is going on top, which is confirmed at survey rather than assumed.
Types of screed
The main options suit different depths, timescales and finishes.
Sand and cement screed
The traditional screed, mixed and laid by hand and trowelled to level. It is versatile, works at a range of thicknesses and is the long-established choice for bringing a floor up to level. It takes longer to dry than a liquid screed, which matters where the programme is tight.
Liquid and flow screed
A pumped, self-smoothing screed that flows out to a very flat, even finish over large areas quickly. Liquid screed is well suited to bigger floors and to underfloor heating, where it flows around the pipes and gives excellent contact. It goes down faster than a hand-laid screed and reaches a flatter finish, though it still needs proper drying time before a surface goes on.
Self-levelling compound
For smaller corrections rather than a full build-up, a self-levelling compound is poured over a sound slab and flows out to iron out minor dips and ridges. It is the usual answer where a floor is basically level but not quite smooth enough for a seamless resin or tile finish.
Screed or self-levelling compound: which do you need?
The two solve different problems. A screed is used where a floor needs building up by a meaningful depth, or laying to falls, or where a new level surface is needed over a rough or broken base. A self-levelling compound is a thinner pour for fine correction, smoothing out the last few millimetres on a floor that is already close to level.
In practice the choice comes down to how far out the floor is and what is going on top. A heavily uneven floor needs a screed to bring it to level, while a sound slab with minor undulations may need no more than a levelling compound before the finish goes down. We confirm which at survey, so the floor is corrected the right way rather than the expensive way.
What to know before you screed a floor
Thickness. How thick a screed needs to be depends on the type and what it is laid over. A bonded screed can be relatively thin, while an unbonded or floating screed, or one over insulation or underfloor heating, needs more depth to stay sound. There is a minimum thickness for each type, and going below it is a common cause of cracking, so the depth is specified to suit rather than minimised.
Drying time. A screed has to dry before a surface goes on, and rushing it is the usual reason a finish later fails. As a rough guide a traditional sand and cement screed dries slowly, often around a day per millimetre for the first stretch, while many liquid screeds dry faster, but both depend on thickness and site conditions. The slab is checked for moisture before the finish is laid rather than worked to a fixed date.
Underfloor heating. Screed and underfloor heating go together well, with liquid screed in particular flowing around the pipes for good heat transfer. The screed depth over the pipes and a proper commissioning and drying period both matter, and these are built into the programme.
Preparation. Like any layer, a screed only performs over a sound, properly prepared base. The surface is prepared and any concrete repairs are carried out first, so the screed bonds and stays put.
What affects the cost of screeding?
Rather than a single rate, the cost of screeding a floor comes down to a few things: the area to be covered, the type of screed, the thickness and build-up needed, how much preparation or repair the base requires and access to the site for materials and pumping. A large, open floor with good access is more straightforward than a tight, broken-up one that needs building up in depth.
Because of that, we survey the floor, confirm the screed and depth it needs and set it out in a clear written quotation, so the screeding is costed as part of the whole job rather than as a surprise later.
Why choose Surface Specialists?
A level, sound, properly dried screed is the foundation a finished floor depends on, and the result comes down to the right screed specified and laid by people who do this work every day. That is what we arrange, with one point of contact looking after the project from start to finish.
- A specialist focus. We concentrate on resin and surface treatment, so the screed is matched to the floor and the finish going on rather than a one-size-fits-all answer.
- Experienced contractors. Screeding is carried out by established specialist contractors with the right equipment for hand-laid and pumped liquid screeds.
- Level and sound. The screed is laid to a true level and given the drying time it needs, so the finish sits flat and lasts.
- One point of contact. From survey through to a prepared, screeded floor, you deal with us.
Screeding is one of our subfloor preparation services, alongside sanding and grinding and epoxy DPM. Learn more about Surface Specialists or explore the full range of resin flooring we cover.
Areas we cover
We arrange floor screeding through experienced specialist contractors and are steadily extending the areas we cover. See our areas we cover hub for local detail, including resin flooring in Manchester, with more local pages being added.
Get a quote
Tell us about your floor and what is going on it and we will arrange a free site survey, then provide a written specification and quotation, typically within 48 hours. There is no obligation. Contact us to get started.
GET A FREE SITE SURVEY & QUOTATION
Frequently asked questions
What is floor screeding?
Floor screeding is laying a levelling layer over a slab to bring it to the right height and give a smooth, sound base for the final floor. The screed sits between the structural slab and the finished surface, making the floor flat and ready to take resin, tiles or another covering.
What is the difference between liquid screed and a sand and cement screed?
A sand and cement screed is mixed and trowelled by hand, is versatile across thicknesses and dries more slowly. A liquid or flow screed is pumped and self-smoothing, flows out very flat over large areas, suits underfloor heating and goes down faster. The right one depends on the floor, the programme and the finish going on.
What is self-levelling compound and how is it different from screed?
Self-levelling compound is a thin pour used to smooth out minor dips on a floor that is already close to level. A screed is a thicker layer used to build a floor up or lay it to level. Compound corrects the last few millimetres; screed does the heavier levelling.
How thick does a screed need to be?
It depends on the type. A bonded screed can be relatively thin, while a floating screed or one over insulation or underfloor heating needs more depth. Each type has a minimum thickness, and going below it risks cracking, so the depth is specified to suit the floor rather than cut down.
How long does screed take to dry?
It depends on the type, the thickness and the conditions. A traditional sand and cement screed dries slowly, often roughly a day per millimetre for the first stretch, while many liquid screeds dry faster. The screed is moisture-tested before any surface goes on, rather than worked to a fixed date, because laying a finish over a screed that is still wet is a common cause of failure.
Can you screed over underfloor heating or an existing floor?
Yes. Screed is commonly laid over underfloor heating, with liquid screed flowing around the pipes for good heat transfer, and over existing floors once they are sound and prepared. The base is assessed at survey and the screed and depth specified to suit.
Which areas do you cover?
We work through a network of experienced specialist contractors and are extending the areas we cover. Contact us to confirm cover for your project.