Jump to content

Screed Thickness


GrantMcscott

Recommended Posts

how do you measure screed thickness is it from the insulation height to the top of the screed or from the top of the pipes to the top of the screed.

 

At the minute I have 75 mm from insulation to top of screed.  Is this to thick?

 

thanks

Edited by GrantMcscott
Link to comment
Share on other sites

it is the total thickness of the screed so, yes, measure insulation to top of screed regardless of pipework. If sand and cement screed then 75mm is about standard. Liquid pour is thinner. I used liquid at about 60mm, personally I find it a bit bouncy on the insulation and it doesnt have a completely solid feel, the kids thumping around can be felt through it. If I had my time again I would have gone with my 150mm concrete slab over the insulation and had the concrete laid to a decent standard of flatness/level and done away with the screed entirely. I havent done sums but reckon the higher spec slab finish is more than covered in the screed savings.  Then I would have put finish floor over, or run a smoothing compound if it was a bit rough, then finished. Slab would possibly need some structural movement joints depending on what you want to put over the top of it.

Link to comment
Share on other sites

1 hour ago, MarkyP said:

If sand and cement screed then 75mm is about standard.

this is what I thought as well but I was talking to an old plasterer/screeder and he said that sand and cement screed can be thinner if you put chicken wire in the screed!! not sure if he was winding me up or not though. I guess anything is possible. ?

 

@nod you ever heard of this?

Edited by Thorfun
tagged nod for comments
Link to comment
Share on other sites

5 minutes ago, Thorfun said:

this is what I thought as well but I was talking to an old plasterer/screeder and he said that sand and cement screed can be thinner if you put chicken wire in the screed!! not sure if he was winding me up or not though. I guess anything is possible. ?

 

Chicken wire will act as reinforcing and hold the screed together/stop it cracking, but do you really want or need to cut down on the thickness? As @MarkyP pointed out, reducing mass of a floor generally results in more movement.

Link to comment
Share on other sites

38 minutes ago, markc said:

Chicken wire will act as reinforcing and hold the screed together/stop it cracking, but do you really want or need to cut down on the thickness? As @MarkyP pointed out, reducing mass of a floor generally results in more movement.

nope. just thought I'd mention it as I was having a discussion with the guy between Anhydrite screed (which we've been specified) at 50mm and sand and cement at 70mm. 

 

thought it was interesting that it's normally stated that 70mm minimum for sand and cement but with the chicken wire (or possibly fibres added to the mix) you could go thinner.

Link to comment
Share on other sites

49 minutes ago, Thorfun said:

this is what I thought as well but I was talking to an old plasterer/screeder and he said that sand and cement screed can be thinner if you put chicken wire in the screed!! not sure if he was winding me up or not though. I guess anything is possible. ?

 

@nod you ever heard of this?

We used to put chicken wire in all the time 

Mainly when going over groups of pipes 

In the days before there where fibers added to the screed 

Ideally you need 50 mil of screed Though I’ve tiled floors that have barely covered the UFH pipes 

Link to comment
Share on other sites

40 minutes ago, GrantMcscott said:

Is there any benifit laying the liquid screed at 75 mm?

 

No most of the liquid screeds are fine at 50mm so the 25mm would be best as insulation if you want liquid.  The cement based ones are easier to tile than the anhydrite ones.

  • Like 1
Link to comment
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
×
×
  • Create New...