Screeds
Screeds for every constraint. Flowing, self-compacting and traditional screeds, including on precast planks, installed with our own placing booms where access is tight and time is short.
The work
We install screeds across upper decks, ground floors and roofs, matching the system to the structure, the finish and the programme. Hospitals, schools, multi-storey frames, data halls and secure facilities all feature, on projects from around £15,000 to £2m and beyond.
Self-compacting and flowing screeds let us cover large areas quickly and reach restricted spaces, without the late working that traditional methods can demand. That is usually the reason we are on the job. If a building has to keep running while its floors go in, the screed system and the placing method have to be chosen together, and most of the market only sells one of the two.
Proof, not promises. You get the surface regularity survey and the records, not an assurance.
Worth settling early, because it is the most common mis-tender we see.
A screed is a levelling layer laid over a base or a structural deck. It creates the finished level and the surface the floor covering sits on. It is not the structure.
An in-situ concrete floor is the structural slab itself, usually power floated to a hard, durable finish that is walked and driven on directly. See concrete flooring.
If the drawings show a structural deck with a topping over it, you want a screed. If the drawings show the slab as the finished floor, you want an in-situ concrete floor. We deliver both, so there is no incentive here to talk you into either.
Pumped, self-levelling, fast over large areas and the best method for underfloor heating because it fully encases the pipes. The default choice for large floor plates and occupied buildings. See flowing screed.
Consolidates under its own weight, so there is no power floating and therefore no late or night working on site. Where the site will not permit finishing crews on the deck in the evening, this is the system that solves it. See self-compacting screed.
Not a different material so much as a different problem. Precast and hollowcore decks on upper floors need the screed getting up there, which is a placing question before it is a screed question. See screeds on precast planks.
Still right for small, chopped-up or heavily detailed areas, for steep falls, and where a bonded screed at depth is specified. Slower and more labour-intensive over a large floor plate, which is why the pumped systems have taken most of the market.
Which binder, and what is going on top? Flowing screeds are broadly calcium sulphate based (anhydrite) or cementitious. Calcium sulphate flows well and is widely used, but it is moisture-sensitive and usually needs its surface laitance removing before adhered floor coverings. Cementitious avoids both and costs more. The finishes schedule should decide this.
Bonded, unbonded or floating? Each has a different minimum depth and a different tolerance for a base that is out of level. Floating over insulation is the normal arrangement with underfloor heating.
What surface regularity class is specified? SR1, SR2 or SR3 under BS 8204. It changes the method and the price.
What is the drying programme? Moisture-sensitive floor coverings drive the drying, and drying often drives the fit-out. This is the item most likely to bite a programme, and it should be designed rather than assumed.
Can the deck be reached? On upper floors this is the whole job. If plant has to be craned up, the price and the programme change. If it does not, they do not.
Screed surface regularity is normally specified to BS 8204, measured as the maximum deviation under a 2m straightedge:
| Class | Maximum deviation | Typically used for |
|---|---|---|
| SR1 | 3mm | High specification floors and demanding floor finishes |
| SR2 | 5mm | The general default for most commercial projects |
| SR3 | 10mm | Utility areas and floors taking a thick applied finish |
SR2 covers the majority of commercial work and is normally what is assumed where a specification is silent. Screed materials are separately classified by binder type under BS EN 13813, which is what the manufacturer's declaration of performance refers to.
Where the work is an in-situ concrete floor rather than a screed, flatness is specified to TR34 as an FM classification instead. Different standard, different test, different survey.
Our own operatives, our own pumps, our own placing booms, start to finish.
Placing is the differentiator. We run our own concrete line pumps and two track-mounted placing booms, which are two of only three in the country. They deliver screed across upper decks and into restricted spaces without craning plant up, which is why we can price work that other screeding subcontractors decline.
Because the plant is ours, the placing method is planned as part of the works rather than bolted on afterwards. Pump positions, hose runs, boom set-up, outrigger loadings and wash-out are all agreed before we mobilise. More on the company and the plant at about Trent.
Pumped screed covers ground fast. The limit is almost never the screed. It is the access, the number of pump set-ups the building allows, the delivery route, and how much of the deck is genuinely ready.
We programme from the ready date backwards. If the insulation, the underfloor heating, the edge detailing or the deck preparation will not be complete when the programme says, we say so at tender rather than on the day the pump is booked.
Constructionline Gold registered, Avetta and SSIP accredited, and a member of the Nuclear Industry Association. Tier 1 main contractors we deliver for include VINCI, McLaren, Costain, Kier, Interclass, Tomlinson, SMD, Actavo, Tarmac and Veolia.
If you tender screed projects regularly, how we work with main contractors sets out what we commit to.
FAQs
Send us the drawings and the specification, and we'll tell you straight whether we can deliver it, and how.
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