How do I choose the right screed system for me?
I’m Andy Parkin, Managing Director of the multi award winning Speed Screed. So, how do you choose the right screeding system?
What Can I do?
I’m going to look at a number of areas that you may consider when you are looking for a system.
First of all, how quickly do you want to get the floor coverings bonded to the surface or laid on the surface? That could be tiles, vinyl, laminates, engineered wood, anything that needs to go on the surface, the screed needs to be dry. Not just visually dry but with enough moisture out of the Screed to allow a bond just for the wood to float on top without affecting the wood itself not absorbing the moisture out of the screed.
If you try and bond too early, it will probably just delaminate and then you have further problems, it’s very important to test the screed before the floor coverings go on. It’s important to decide before the screed goes in, just how quickly you need those floor coverings laid on your program or we can provide screeds that you literally can tile after a matter of hours.
Now, that might not be your particular requirement but it’s just to let you know that we’ve got anything from a matter of hours to standardised times.
Depending on the thickness of the screed this would normally affect the drying times, you could be looking at 3 months for a typical screed to dry, and for it to be ready to accept the floor coverings.
You can put a liquid D.P.M on top of the screed, but it would be far more cost effective to start out with a fast-drying screed to start with. You know when it’s going to dry and when you should be able to put your floor coverings on.
Another thing to consider would be when can you actually walk on it? There is light foot traffic and then there is full site traffic. The screed would always need to be protected until it is actually covered. Generally, levelling screeds are not wearing surfaces so, over a period of time if they’re not protected they can get damaged. You can see wear on the surface, and so generally it would be protected.
When can you actually walk on the screed? Again, we can provide products where you can walk on the screed in a matter of hours. A traditional screed may take longer, depending on the on the weather relating to temperature. It could be around 5 days to actually have light traffic. For full site traffic it could be longer. For specialist products we would be talking 24 hours to supply as an alternative. When compared with anything from 3 to 7 days for other products.
It is important to decide when do you need to be trafficking, when do you need all the trades people on the surface of the screed.
Another thing to consider might be the loading of the screed. This might be fixing into the screed, this or perhaps you’ve got to pass some plants or machinery across the screed and it needs to have a certain amount of strength to resist the load placed upon it. This is something to consider and if there is a requirement for loading, a structural engineer will then be able to tell us what the load is, we would be able to accurately provide the screed that will have the strength required to resist that particular load, and it could be early loaded.
Will the Screed have underfloor heating? That is something that may determine the type of screed, it may be that you are looking for a dense screed that’s going to give good thermal conductivity?
It maybe that you’ve only got a certain depth of screed that you can go down to? That may change the type of screed that you’re going to put need, certainly on the underfloor heating or in other applications.
Depending whether it’s going to be bonded onto a concrete substrate, whether there’s a membrane, whether you have insulation there, all of these will determine the depths of screed required. Certain screeds will perform to thinner depths, and if you can come up with a profile of the screed, it’s then easy to find the characteristics of that screed and can match what you actually require.
Other things to consider from the system as a whole would be:
- Do you require insulation? What type of insulation? What strength are you going to need? What compressive strength? What is the thermal resistance of that insulation? Is it there for thermal performance or is it there for voyage fill? There are lots of considerations around insulation, it’s very important to get the right system. If you are trying to achieve a certain u value, we can calculate that for you to ensure that you get the correct system.
- Acoustics is another thing that needs to be considered. There is a requirement for multi occupancy buildings that they’ve got to meet a certain decibel, it’s part L of the building regulations. That might be a consideration for multi occupancy buildings, or it could be school, and you want to apply acoustics. At home you may want to apply acoustic insulation too.
- Membranes? Is there a requirement for a damp proof membrane? It may be fresh concrete that the screed is going to be going on to. The concrete will have a high moisture content, potentially for up to 12 months depending on the thickness. You don’t want the available moisture going into the screed and delaying the drying times. Membranes might be used to suppress that moisture.
- Slip membranes? It is best practice to place a slip membrane over insulation especially for your foil backed insulation.
There are lots of things to consider, and the best thing to do is to fact find. Come up with a list of necessities, you may have a list of things that you’d like and then it might come down to cost.
But you may have a list of things that you definitely need for the project and we can design that system, to tailor for your exact needs. We love to help, please contact us.