Flow Screed Minimum Thickness?

Flow Screed Minimum Thickness

I’m Andy Parkin, Managing Director of the Multi-Award Winning Speed Screed.  Just what is the flow screed minimum thickness?

Do you need to know the flow screed minimum thickness?

It is a question that we are often asked  “I’ve only got 10mm, I’ve only got 20mm. Is it okay for the flow screed?” I’ll try to answer that here and now for you.

When we’re talking about flow screed minimum thickness, generally, we are talking about the calcium sulphate version.  This is the one without cement and has a calcium sulphate binder, as opposed to the cementitious version. There is a cementitious version, but it currently only accounts for a very small percentage of the market of the flow screed.

If you have a structural floor and you need a screed on top, then this product is ideal. It can be used in bonded, unbonded, floating construction, floating construction with or without underfloor heating pipes. It is suitable for residential and commercial floors.

Bonded Screed

There is a specialist calcium sulphate flow screed that has been designed to go very thinly bonded and unbonded.

  • Bonded to the substrate 15mm for specialist screed, and 25mm for standard flow screed.

You must make sure the substrate is clean, sound, dry, and isn’t contaminated. It may require some surface preparation before the screed is laid, because the bond is only as good as the substrate. If the substrate is not good, then you are not going to get the required bond, and it will delaminate.

Unbonded Screed

Unbonded is when you have a membrane between the substrate and the screed.  This could be a slip membrane or  a DPM.

  • Unbonded 15mm for specialist screed, and 30mm for standard flow screed.

Floating Screed

Floating construction could be screed on either thermal or acoustic insulation.

  • Floating 35mm domestic and 40mm commercial
  • Floating with underfloor heating 35mm for specialist screed, and 45mm for standard flow screed

I do hope that helps with flow screed minimum thickness, if you have any further questions please get in touch.

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flow screed minimum thickness

flow screed minimum thickness