Avoiding frozen pipes in insulated loft

Canucklehead

silvercar wrote: »

Haven't a clue. Too far into the loft to see and can't really get about in the loft easily, now that there is 30cm of insulation on the loft floor.

The lagging would have been done some time between 1937 and 2006, so very much doubt it is (or would needed to have been) part L compliant.

So assume inadequate lagging of pipes. Water tank is itself in expanded polystyrene lagging with lid and no insulation directly below tank.

All I can suggest is to get a bread knife or similar, cut the lagging, fold back and create a path through it. At some point you might need to anyway to get to pipes and tanks.

I would say there is a risk of freezing if the insulation is to old standards with added fibreglass on the loft floor stopping heat rising.
At the moment you have the choice of leaving the hatch open or insulating the pipes.



GSR.

silvercar

At the moment you have the choice of leaving the hatch open or insulating the pipes.

I feel I'm going round in circles.

At what temperature pould it be prudent to leave the hatch open.

Clearly a minimum forecast temperature of 0C wouldn't be enough to freeze the pipes due to:
a) latent heat
b) insulation not being a total block on rising heat
c) the roof and lining offering some protection

So I'm seeking suggestions on what the minimum forecast temperature would need to be to make it sensible to open the loft hatch.

silvercar

Any opinions?

ally18

Hi,
Can I add my bit, just to let you know my pipes have frozen over night. Temp this morning at -13c. No cold water upstairs at all but still coming from mains so has to be frozen up in the loft. I have a loft conversion which means the room immediately next to the tank and pipes was heated but didn't stop this happening.

annscullamus

My hot water pipe in loft burst on saturday and ruined 3 rooms. Open the loft hatches and let some warm air rise - and we had only about 3 inches of snow, but the plumber who stopped the burst said to keep all loft hatches open in low temperatures.

I wish I had known that last week. £25,000 is the insurers estimate for a 'rip out' job, and that is not including the contents losses.

The insulated roof meant that the lagged pipes just could not keep the water above freezing.

bigmike20vt_2

wow that is some scary reading!,

my central heating packed up 24 hrs ago, and an engineer will not be with me till either tomorrow or thurs.

i had the loft and wall insulation done in the summer (so at least the pipes are - well i hope - lagged

but it does mean i am unable to keep the house warm.

it was "only" -7 degs C last night, i really hope that is not enough to cause a burst!.

Good luck everyone.
M.

SuzieSue

annscullamus wrote: »

My hot water pipe in loft burst on saturday and ruined 3 rooms. Open the loft hatches and let some warm air rise - and we had only about 3 inches of snow, but the plumber who stopped the burst said to keep all loft hatches open in low temperatures.

I wish I had known that last week. £25,000 is the insurers estimate for a 'rip out' job, and that is not including the contents losses.

The insulated roof meant that the lagged pipes just could not keep the water above freezing.

Oh dear. I'm sorry to hear that and thanks for the advice. Do you switch your heating off overnight? I keep mine running with the thermostat at 12 degrees, I don't know if that would prevent your pipes freezing?

SuzieSue

bigmike20vt wrote: »

wow that is some scary reading!,

my central heating packed up 24 hrs ago, and an engineer will not be with me till either tomorrow or thurs.

i had the loft and wall insulation done in the summer (so at least the pipes are - well i hope - lagged

but it does mean i am unable to keep the house warm.

it was "only" -7 degs C last night, i really hope that is not enough to cause a burst!.

Good luck everyone.
M.

I would invest in some electrc heaters and keep the loft door open.

silvercar

As an experiment I put a digital thermometer in the integrated garage. The garage has no heating and two outside walls. I presume the two inside walls are thick enough that heat doesn't pass through to the garage but offer some protection from the elements. The exposed walls face north-east and south-east. I'm guessing that the temperature in there would be similar to that in the loft, where the roof is effectively four outside walls but there may be some slight heat coming through the well insulated floor.

My car thermometer showed and outside temperature of -1C when the inside temp was showing 5.5C, so a difference of 6.5C.

Inforapennyinforapound

Just to add my thoughts :

silvercar,i think it prudent to leave the hatch door partially open day and night with present temperatures.Better safe than sorry surely?

I have same set up as you.i.e loft insulated and hot/cold pipes lagged.In fact i was up in loft today and it was lovely and warm so fingers crossed all will be ok.

I have also lagged heavily outside tap ,and at night i leave a couple of kitchen base unit doors open where there are water pipes including where the rising main and stopcock are located....over the top? maybe but we had no water 2 days ago when a nearby water main several feet underground burst leaving the community 'waterless' ans very inconvenient it was too.