hi guys I'm building my own house in norfolk its a solid wall constuction with ground floor block and beam and first floor with 215 mm hollow core concrete slabs externally 200 mm insulation with a thin coat render system .

my background is ive been a bricklayer for over 40 years and also specialised in machine rendering/plastering and also pumped floor screeds hopefully I can be of help on this forum

!!

Sounds good throw some pics up or start a blog if you get time

Hi. 

I will be asking about floor screeds soon, keep your eyes peeled. 

where are you in uk

edit --stupid question --me not reading you post correctly --too early 

Edited February 14, 20206 yr by scottishjohn

3 hours ago, col57 said:

[...] specialised in machine rendering/plastering and also pumped floor screeds hopefully I can be of help on this forum

 

 

Morning, welcome.

Could you help me please? How flat is a flat screeded floor: what's a permissible deviation from a target level?

hi anonymous bosch I've just ordered 6 pallets of weber 4310 a flow screed i will pump this over my ufh pipes to a total depth of 30 mm including pipes it will be as flat as glass with the added bonus you can walk on it after 2 hrs 

Morning @col57 is that right 30mm, so if you have a 16mm pipe for your ufh you only have 14mm coverage over the pipes. 

Im intrigued tell us more, I am looking at increasing my screed thickness as 50mm of a flowable screed is worrying me.  

hi russell griffiths the weber 4310 is fibre reinforced and in my view the best pumpable screed on the market the thinner it is the quicker it drys check it out on the weber website !

3 hours ago, col57 said:

hi anonymous bosch I've just ordered 6 pallets of weber 4310 a flow screed i will pump this over my ufh pipes to a total depth of 30 mm including pipes it will be as flat as glass with the added bonus you can walk on it after 2 hrs 

I am guessing you have concrete+ insulation below the pipes?

If not then what 

and screed is just the finishing coat 

scottish john downstairs is block and beam 250 mm insulation upstairs is concrete slab with 70 mm insulation both floors have 16 mm ufh pipes total of 30 mm screed  and both floors are tiled 

I guess we know who to ask about screed now. Is that 30mm over the pipes or 30mm total? 

 

We quite often get questions about the minimum floor build up for UFH. I've seen a system that was ok with 40mm screed but interested to know if thinner is possible.

 

 

temp the screed is 30 mm total 

That gypsum based stuff which gets done at 50mm is Bombproof. Have worked ontop of it before

^ what we've got.

 

gypsum based screed is good till you get a flood or leaking pipe and then its mush!

9 hours ago, col57 said:

temp the screed is 30 mm total 

 

 

Many here prefer a thicker screed with UFH because:

1. The floor can absorb more heat during the cheap overnight tarif.
2. Such a thin screed will exhibit hot spots with UFH piping at a regular spacing.

What is your opinion on these points?

 

 

1 hour ago, col57 said:

gypsum based screed is good till you get a flood or leaking pipe and then its mush!

Really?!

yes mate really 

Sure the one I worked on went in before Windows and doors. 

On 15/02/2020 at 09:27, col57 said:

hi russell griffiths the weber 4310 is fibre reinforced and in my view the best pumpable screed on the market the thinner it is the quicker it drys check it out on the weber website !

Have you used the Weber 4610 Pro Top..? Thinking of leveling a garage with it as you can use as the wearing surface. Seems to be about £21 a bag inc VAT so much cheaper than epoxy. 

hi peterw used it briefly at the weber training school but not on site like most of the floor products its reliable and does exactly what it says on the bag  you must however observe the mixing conditions ie if it says mix for  a specific time  and add a specified amount of water you will not have any problems