Buyers Guide to Screed and Underfloor Heating

What is Dry Screed?

Dry screed is a mixture of cement and coarse sand that needs water to get it to the consistency required for the flooring. You may also want to consider adding fibres to the mixture so that the risk of the screed cracking is reduced.

The screed is laid manually by piling it up within sections to get to the necessary height when it can then be levelled off with a smooth finish. This type of screed will typically take approximately 28 days to thoroughly dry. However, this is an average and the actual drying, or curing time will depend on the environment that it is in and any additives you have included in your screed mixture.

If you have a small area of flooring or you need the curing time to be lower, dry screed is going to be the best option for you. 

What is Self-Levelling Screed?

Self-levelling screed doesn’t require the same amount of effort as dry screed as it will even itself out on the surface it is poured onto. The screed is made from calcium sulphate that is added into sand, water and chemicals. This mixture creates a liquid screed that is ideal for large surfaces and removes the risk that voids will form within the mixture.

 

Whilst self-levelling screed makes the process easier, it does take longer to cure than dry screed. You will also require a vapour barrier to protect the floor insulation from damage. You should factor in this additional time when planning your underfloor heating project.

 

If you have a large area of flooring that needs to be covered and the length of the curing time is not an issue, then self-levelled screed will make your project run much more smoothly.

When to Use Your Underfloor Heating