Floor Screeding Guide: How to Choose the Right Screed
Author: Co-Dunkall Ltd || Date: 3rd August 2026
Floor screeding is the process of choosing the right screed based on your project type, timeline, whether you’re installing underfloor heating, and your budget. In this guide, we’ll walk you through the main screed options—liquid screed and sand & cement screed—so you can make an informed decision for your domestic or commercial build.
Key Facts: Floor Screed Types
- Liquid (flowing) screed: self-levelling, faster to lay, excellent for underfloor heating, typical depth 35–50mm
- Sand & cement screed: traditional, hand-laid, bonded or unbonded, typical depth 65–75mm
- Drying times: liquid screed typically 1mm per day up to 40mm, then 0.5mm per day; sand & cement 1 day per mm thickness
- Foot traffic: usually 24–48 hours for both, but full cure varies by depth and type
Why Floor Screeding Matters
Floor screed is the smooth, level layer applied over a concrete subfloor or insulation. It provides the base for your final floor finish—tiles, carpet, vinyl, timber—and encases underfloor heating installation pipes if fitted. The right screed ensures excellent thermal performance, a durable finish, and a seamless surface across large areas.
We’ve been installing screeds across Norfolk, Suffolk, Cambridgeshire, Essex and Hertfordshire since 2008, and the most common question we hear is: which screed should I choose?
Liquid Screed vs Sand & Cement Screed
Liquid screed (also called flowing screed or anhydrite screed) is a self-levelling, pumpable mix. It flows into place, requires minimal manual finishing, and can be laid much faster than traditional screed—our team regularly lays hundreds of square metres in a single day. Liquid screed is thinner (typically 35–50mm over underfloor heating pipes), which reduces floor build-up and improves heat transfer. Brands such as Cemfloor and Isocrete K-Screed are commonly specified. Because it’s poured, it creates a seamless finish with fewer joints and less risk of cracking.
Sand and cement screed is the traditional method: mixed on-site or delivered ready-mixed, then hand-laid and compacted by trowel or beam. It’s robust, well-understood by trades, and cost-effective on smaller or simpler projects. Typical thickness is 65–75mm for an unbonded screed (laid over a damp-proof membrane), or 25–40mm when bonded directly to a prepared concrete slab.
Which Screed for Underfloor Heating?
If you’re installing underfloor heating, liquid screed is usually the better choice. Its fluid consistency means it completely encases the pipes with no voids, maximising heat conduction and thermal efficiency. The thinner profile (compared to sand & cement) means quicker warm-up and cool-down times, which translates to lower running costs. We install underfloor heating systems alongside liquid screed on the majority of our new-build and extension projects across East Anglia.
Sand & cement screed can also be used with underfloor heating, but the screed depth must be greater (typically 65–75mm over pipes), which increases floor height and thermal mass. It’s a proven combination, particularly in refurbishments where floor levels are less critical.
Drying Times & Project Scheduling
Liquid screed typically dries at around 1mm per day up to 40mm thickness, then 0.5mm per day thereafter. A 50mm liquid screed may take 60–70 days to dry fully before you can lay impermeable floor finishes such as vinyl or resin. Foot traffic is usually permitted after 24–48 hours, and underfloor heating commissioning begins after around 7 days.
Sand & cement screed dries at roughly 1 day per mm of thickness under good conditions. A 75mm screed may need 75 days before final finishes—though breathable finishes like carpet or engineered timber can sometimes be laid sooner. It’s critical to allow proper curing; we always provide aftercare guidance tailored to the screed type and project.
Insulation & Floor Build-Up
Modern building regulations require high-performance floor insulation, particularly in new builds and extensions. We supply and install rigid insulation boards (such as Kingspan, Celotex or Cellecta) beneath the screed. Liquid screed’s thinner profile means the total floor build-up—insulation plus screed—can be kept lower, which is a game-changer when floor levels and door thresholds are tight.
For acoustic insulation in flats or commercial buildings, products like Cellecta Yelofon (a high-density foam) are laid below the screed to reduce impact sound transmission.
Cost Considerations
Liquid screed typically costs more per square metre than sand & cement screed in material terms, but the faster installation often offsets this—especially on larger projects where speed matters. Sand & cement screed is generally more economical on smaller areas or when labour costs are lower.
The total cost also depends on insulation type, underfloor heating, screed depth, access, and site conditions. We always provide a detailed, fixed-price quotation after a site visit or review of your drawings.
Frequently Asked Questions
Can I lay floor screed myself?
While sand & cement screed can be mixed and laid by a competent DIYer, achieving a level, crack-free finish over a large area requires skill and the right equipment. Liquid screed must be mixed and pumped on-site by trained operatives—it’s not a DIY-friendly material. For both types, we recommend professional installation to ensure quality and compliance with building regulations.
How long before I can walk on new screed?
Both liquid screed and sand & cement screed typically allow light foot traffic after 24–48 hours. However, this does not mean the screed is dry or ready for floor finishes—full cure takes weeks. Always follow the contractor’s aftercare instructions.
Do I need underfloor heating with screed?
No—screed is simply the levelling layer for your floor finish. You can have screed without underfloor heating. However, if you’re planning underfloor heating, it’s far easier and more cost-effective to install it before screeding, rather than retrofitting later.
What’s the minimum and maximum screed depth?
For liquid screed over underfloor heating, the minimum is typically 35mm above the pipes; maximum depends on the product but is often around 100mm. For unbonded sand & cement screed, 65–75mm is standard. Bonded sand & cement can be as thin as 25mm if the substrate is prepared correctly. Thicker screeds take longer to dry and add more weight to the floor structure.
Can screed be laid in winter?
Yes, but the building must be weather-tight, frost-free, and ideally heated to at least 5°C. Liquid screed in particular benefits from stable conditions during curing. We work year-round across Norfolk and Suffolk, and always assess site conditions before scheduling a pour.
Our Recommendations
- New builds & extensions with underfloor heating: liquid screed for speed, thermal performance and seamless finish
- Smaller domestic projects without UFH: sand & cement screed for cost-effectiveness and simplicity
- Commercial projects with tight programmes: liquid screed to reduce installation time and get trades back on-site sooner
- Refurbishments with height restrictions: liquid screed to minimise floor build-up
- Acoustic performance (flats, schools, offices): liquid or sand & cement screed over specialist acoustic insulation
Why Choose Co-Dunkall?
We’re East Anglia’s largest floor screeding company, and we’ve been laying high-quality screeds since 2008. Our team installs both liquid screed and sand & cement screed, along with underfloor heating, insulation and floor preparation. Every project—whether a 50m² extension in Norwich or a 500m² commercial slab in Ipswich—receives the same care, attention to detail, and expert aftercare advice.
We provide free, no-obligation quotations, and we’re always happy to talk through your options over the phone or on-site. Call us on 01953 488224 or email info@co-dunkall.co.uk to discuss your project. Our head office is in Carbrooke, Norfolk, and we cover Norfolk, Suffolk, Cambridgeshire, Essex and Hertfordshire.
Floor Screeding, Liquid Screed & Underfloor Heating – Norfolk, Suffolk, Cambridgeshire, Essex & Hertfordshire
