Jump to content

Underfloor and screed in before windows


Gem77

Recommended Posts

Hi All

 

Just reaching out for advice on something that has happened our on build.

In short we have had the underfloor heating installed and screed laid before the windows have been installed.

Should we be concerned about this as the winter is now approaching and its not likely that we'll have windows in before Christmas? Will the screed or underfloor be damaged by the cold weather?

 

Thanks!

 

Link to comment
Share on other sites

8 hours ago, PeterW said:

Neither will be damaged by cold, but if you can get an airline in to blow the water out of the pipes it would be good if you can’t seal up the whole building as @ProDave says. 

That's great - I don't actually think there is any water in yet - they have run an air test. 

Link to comment
Share on other sites

Even in Arctic conditions, they would be fine as long as the pipes are taped and not capped off with a tightly sealed fitting. They need to allow air in and out for expansion. 
After that just make sure the pipes are fixed so they can’t become kinked at the slab. It’s VERY easy to kink them if they’re pulled / pushed on ( but conversely it’s very hard to damage them otherwise ).

Blow down one and see if you can easily do so, and that will tell you that no water resides in them. 

Link to comment
Share on other sites

5 minutes ago, epsilonGreedy said:

Has everyone forgotten the first episode of most recent Grand Designs series. No windows and water left in the UFH pipes, resulted in destruction of the screed as the pipes froze.

 

opps! so i presume once the UFH pipes are laid (even before the screed goes down) get the ends capped off and sealed

Link to comment
Share on other sites

20 minutes ago, Moonshine said:

 

opps! so i presume once the UFH pipes are laid (even before the screed goes down) get the ends capped off and sealed

You do that regardless, to stop contaminants entering ( and later blocking ) the pipes, but yes, get them taped off, not capped off, instantly after installation. 

Link to comment
Share on other sites

3 hours ago, Moonshine said:

opps! so i presume once the UFH pipes are laid (even before the screed goes down) get the ends capped off and sealed

 

 

I think the problem is what is the default pressure test method by the installer. I discussed the freezing risk with one screed/ufh installer and his reply was "well we could pressure test with air instead of water or maybe put in an antifreeze for the winter". I did not follow up and ask what the antifreeze might do to the pipes.

Link to comment
Share on other sites

2 hours ago, epsilonGreedy said:

 

I think the problem is what is the default pressure test method by the installer. I discussed the freezing risk with one screed/ufh installer and his reply was "well we could pressure test with air instead of water or maybe put in an antifreeze for the winter". I did not follow up and ask what the antifreeze might do to the pipes.

If it's proper central heating inhibitor / antifreeze, none whatsoever.

 

25% will usually prevent freezing down to about -10

Link to comment
Share on other sites

2 minutes ago, ProDave said:

If it's proper central heating inhibitor / antifreeze, none whatsoever.

 

25% will usually prevent freezing down to about -10

 

Good to hear this. My concern was that the solvent type characteristics of the anti freeze might weaken the plastic ufh pipes. 

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...