Will my pipes freeze?

paperclap

Hi all,

Obviously we’re in a bit of a cold snap right now. And, an energy crisis. Goes hand in hand - yay.

Anywho. Here’s the deal. We’ve a reroof, so new felt.

Pipes in the loft are lagged with the cheap-o stuff from Screwfix. Mitres aren’t sealed that well.

The forecast is -4° on some nights, for a fair few hours.

Reckon they’ll freeze?

Thanks!

MikeJXE

Are the pipes over or under loft insulation ? 

grumbler

What changed compared to what it used  to be? No tiles? They don't add much in terms of thermal insulation.

IMO, pipes in the loft have to be insulated reliably. What stops you from doing this now?

paperclap

Pipes will be on top of the insulation. I say will be, as our roofer is yet to do the insulation at ceiling level.

Before the reroof, we had no membrane. Our old bitumen felt was shot. So, it was quite drafty up in the loft beforehand.

MikeJXE

So are you saying the pipes are clipped in place 270mm  above the ceiling joists because thats how thick the insulation should be, you need to better insulate them or keep your fingers crossed 

diystarter7

Hi OP

Have long is you living there?
Do you have CH and is it turned on and if so how long.
Water tank in loft?
do you use the upstairs basin/bath/shower w/c to circulate water etc?

Does the rook have felt on the inside under the tiles and is it drafty in there EG holes in roof and or air vents.

Thanks

Section62

paperclap said:

The forecast is -4° on some nights, for a fair few hours.

Reckon they’ll freeze?

If you are worried then temporarily leave the loft hatch open a crack.  It will cost you a bit more for the heating or make the house feel colder, but the warm air from the house should keep the pipes above freezing unless it turns full-on Siberian Winter.

Alternatively/additionally, get a reasonably cheap min-max thermometer and keep it in the loft.  See how cold it actually gets overnight for different outdoor temperatures.  Or invest a little bit more in an electronic one with a frost alarm function... opening the loft hatch a bit if the alarm goes off.

paperclap

The pipes are weirdly hoisted on pieces of wood above the ceiling joists.

Yes, we have brand new roofing membrane.

The pipes are insulated with this:
https://www.screwfix.com/p/economy-pipe-insulation-15mm-x-13mm-x-1m/72357

grumbler

paperclap said:

Pipes will be on top of the insulation. I say will be, as our roofer is yet to do the insulation at ceiling level.

I think they will be on top of the joists, and the insulation between the joist isn't up to the modern standards. You need another layer that will cover the joists and the pipes.

ATM, without any insulation, the temperature in the loft is unlikely to drop below zero because of big heat leak through the ceiling.

Norman_Castle

paperclap said:

Before the reroof, we had no membrane. Our old bitumen felt was shot. So, it was quite drafty up in the loft beforehand.

Did they freeze then? Last year I found an uninsulated 3 foot long piece of cold water pipe running at 45 degrees directly under the roofing felt. It had remained unfrozen through an extended -10 degree winter. The ceiling below is lagged and none of my visitors have suggested I'm generous with the heating.

"The pipes are insulated with this:"
https://www.screwfix.com/p/economy-pipe-insulation-15mm-x-13mm-x-1m/72357

Mine too, its fine although gaps can appear where it joins. Not sure if foam insulation shrinks over time. I've got some very old green stuff which has also shrunk. I put loft insulation in the gaps.

paperclap

These are some areas of unlagged pipe, or not finished, if you like.

Didn’t freeze last year, no! Can’t really recall what the temps were like last year though.

It didn’t actually feel that cold up in the loft just now. Almost the same temp as the house, haha!

Maybe I’m over worrying?