Many people confuse drying time with setting time. Most screeds are set hard enough to walk on after two days. The drying time is the amount of time it takes for the screed to be dry enough to apply floor
finishes. Some traditional screeds are dry enough, to apply finishes, within 24 hours but also come with a premium. Others are dry enough for floor finishes after approx two days and are much more
cost-effective. Standard screed dries at about one day per millimetre. It would be advisable to get your screeding works done as early as possible, to save on costs, normally this is as soon as the
building is watertight. This can seriously reduce the cost of your floor screeding package. It must also be said that the screed will need to be protected from any other wet trades spillage. Flowing
screeds dry at a rate of about 1 day per millimetre at best, but are normally applied thinner which can lead to the screed drying between 35 - 50 days. All comparisons, of flowing screed and traditional screed,
done by flowing screed applicators, use the worst technical data of a standard 1:5 traditional screed. It is best to keep an open mind on any type of screed you use, as both can have their advantages.
With traditional screeding any expansion joints can be cut into the screed during laying, this will leave both sides at the same height and it can be done very straight indeed. If the screed is going to get a
tile finish it is best to work out where a tile joint will be and that any joint should fall within that line.
The Pitfalls of not using a quality screed installer
You would expect that all screeding work is the same. Unfortunately many screeds are done quite poorly and leave a very unsatifactory result. Many of the pitfalls are list below:-
Mix - If the mix is done badly the end result is going to be bad too. Do not accept a screed mixed in a drum mixer of any sort. The end result will be a ‘load of balls’ literally! We
only use premixed fibre-screed or site-batched using a forced-action screed pump.
- The screed needs to be laid with a lot of downward force using an aluminium straight-edge. If the a lot of holes in the screed have to be filled with the plastic float the end result wont be too good. A badly compacted screed may break-up in a small amout of time. Any holes in the surface of a screed probably indicates poor compaction. If you believe this is the case, it would be advisable to have your floor hammer-tested by an independent technician prior to having finishes installed. The hammer always bounces off screeds done by us, as they are very highly compacted, with results varying between 0.0 and 0.2mm. Any reading over 3mm is a failure!
Level - An out of level floor is an awful thing to have in a nice home. We use a Water level or a Rugby laser level. Our screeds are typically done to a tolerance of 3mm throughout a full house.
Surface Regularity (SR) - Surface regularity is the part that makes your floor tiles or wooden flooring look the part. If tiles were laid on a poor SR floor, without smoothing, the result would be
diabolical. Luckily floor tilers will try to level up the screed as much as possible prior to fitting tiles, though this is a time consuming job. Tilers don’t have to do this on our floors, just as
they should not have to. \you would be hard pressed to be able to fit a 2p piece, under any part of a 3m straight-edge, placed anywhere on a floor that we have screeded. This dramatically reduces tile
adhesive and the tilers time on any tile installation.
- The finish of the floor screed doesn’t necessarily need to be that tight on a floor that is to have a tiled or wooden floor finish, but if the floor finish is to be vinyl, resin or carpet, an open texture could be detrimental. For a vinyl / carpet finish a poor finished screed may need to have smoothing compound applied. Resin may need to have extra layers done. ADH Flooring Ltd leave a very tight finish and much of our work is powerfloat finished, giving the tightest finish possible.