TOTAL Newbie - Which screed should I go for.

Not open for further replies.


New Member
Hi all

I am building an extension in my house (Single story 34sq meters). It is going to be a kitchen diner and living room area. I live in Stanmore (NW London).

I want to have underfloor heating installed (wet system).

I have no idea what type of screeding to go for. My initial gut instincts was to go for a liquid screed as it would be guaranteed to be 100% level. After a small amount of research I now have doubts whether it is the right move. Apart from being rather expensive for liquid screeding with the problem regarding laitance and no doubt other problems that I've no idea about. No doubt there are advantages and disadvantages to both ways.

Can anyone advise me as to which direction I should be going in. All advice would be really appreciated. If there are any additional questions to help you get to an answer please don't hesitate to ask.

Are you not using a builder ? Seems sand and cement screed would be ideal , for a small floor like that , not sure about access on the build :confused: but would go ready mixed s & c with fibres and a 24 hr retarder . Once you have had the floor layed , wait 48hrs wet the floor and cover with a plastic sheet leave for a week and you will have a top floor surface .
Last edited:
When you get into all the technical crap to do with screeds they say that the liquid ones are more efficient for underfloor heating. With less air pockets in than a traditional screed and able to go down thinner the heat transfers into the room quicker.

The laitance as you said is cleaned off the screed about 6 weeks latter using a big floor sander. For such a small area it will work out more expensive than traditional screed.

Traditional screed is good and is only as level as the guy putting it down. So if you were planning On doing it yourself and have never done it, I'd get someone in. The same goes for the liquid screed, this will be flat not always 100% level. Check some of the companies tolerances, you'd be surprised how much they can fluctuate.

The main thing it boils down to is how much you have to spend and what thickness screed you have allowed for when building. I could be wrong but I'm pretty sure thickness for traditional needs to be 75mm for underfloor and liquid is 50mm.

Hope that helps.
Although I'm doing a fair amount of the work I've decided not to do the screeding or bricklaying as it's something I've never done before. This is my house and I don't want to mess it up. I don't want to leave any link on here with the company I was looking at using otherwise it might look like I'm advertising!!!
Thank you bodders13. As it's my own house I don't mind spending the money on it but I like to make sure I'm not getting ripped off. I'm definitely leaning towards liquid screed as it would appear that with the laser levels etc it will be level everywhere.

Although this is a more expensive method I think it is the right move. What put me off was when I read about what you've got to do to it afterwards and also the moisture test etc.
hopefully the company will have a floor layer , if not go with recommendations :RpS_wink:
dont believe all you read , especially on forums there full of crap , ssssshhh between me and you .
You could have a nice deep pastal coloured resin floor. If I was doing my own build I would never go with the old carpet jobby
Liquid screed is no more likely to be level/flat than a well laid S&C screed, don't believe the hype it doesn't level itself like water.
Liquid screed is no more likely to be level/flat than a well laid S&C screed, don't believe the hype it doesn't level itself like water.

I'll have to take your word for that BUT, from what I've read from loads of different web sites, it is definitely better to use in conjunction with underfloor heating.
Not open for further replies.