# Burst pipes in Attic



## dewdrop (26 Oct 2011)

as the nights get colder memories of last year come to mind.  Since then i got the floor of the attic insulated but the inside of the roof (house built in 1930) has no protection except something like mortar on some of the inside of the slates..most has fallen off. I am now told that because of the floor insulation the attic will become much colder. If i have the central heating on with the trap door to the attic slightly opened will this prevent frozen pipes in the attic. As far as i can see most of the pipes are lagged. I have read about having light bulbs, heaters etc but i would  prefer to keep it simple if at all possible


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## onq (26 Oct 2011)

Having insulated the attic at 1st floor ceiling level and then leaving the attic open to stop your services freezing defeats the purpose of the insulation.
This is why I advise people to consider insulating by following the line of the roof with the insulation, ventilating in accordance with Diagram 11, P. 28 TGD F 2009, Ventilation.
The services should therefore lie within the insulated volume and be protected from the worst ravages of the winter freeze.
However in the case of a house of this vintage, the kind and positioning of the insulation should be carefully considered - and its not something I would advise on off the cuff through AAM.

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Working within your current set up, the simplest suggestion on AAM last year was to install a heat source in the attic for the coldest days - this is the light bulb solution you said you didn't want to install.

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Leaving your attic trapdoor open is a good way of increasing your heating bills and causing draughts all around the house, but it should help prevent pipes freezing.
However even this is not a foolproof method since heat rises and there is no guarantee the air will circulate to all part of the attic pipes in which pipes may be laid.
One thing you must be sure of is making sure there is no insulation under your water tank(s) and making sure the insulation at ceiling level joins with the insulation on the side of the tank. Your tank should have an insulated cover and all pipes to and from it should be lagged for their full length.

Yet in your attic your roof has also lost all its windproofing - the snots of mortar filling the gaps between the slates - without these your roof is basically an "open" structure through which air can move at all levels and which will freeze more readily in cold and windy weather.
My best advice is to have your house re-roofed with a well-considered weathering and insulation solution.

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Heating and attic is a simple thing, but tracing the routes of pipes and  ensuring they are proofed against harm from cold ingress is less  simple.
"As far as I cam see..." suggests that you are not fully aware of all the service routes in your house.
There may be risers and drops in the house in inaccessible areas and in  corners which are currently cold bridges - if unlagged, these pipes can  also freeze.


ONQ.

[broken link removed]

All advice on AAM is remote from the situation and cannot be relied upon                                             as a defence or support - in     and    of        itself  -         should       legal        action        be           taken.
Competent legal and building professionals should be asked to advise in                                             Real Life with rights to    inspect     and       issue         reports    on     the         matter    at  hand.


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## Mpsox (26 Oct 2011)

You're correct that the attic will get colder after you've insulated the attic, this was one of the things we found last winter after we had it done. Lagging pipes does help, but make sure they are all lagged, again we found last winter that we had about a foot of a pipe going into the water tank that wasn't lagged, and that kept freezing until we did it.

Check you're roof tiles as well, you'd be amazed how much cold air can get in if there are any damaged


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## Leo (26 Oct 2011)

You could put a Frost Watcher heater up there. These have a thermostat that will switch the heater on as the temp approaches freezing point. This should set you back ~€15/20.
Leo


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## lowCO2design (26 Oct 2011)

Leo said:


> You could put a Frost Watcher heater up there. These have a thermostat that will switch the heater on as the temp approaches freezing point. This should set you back ~€15/20.
> Leo


would it be easier in the long term to insulate the pipework and the water tank?


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## Leo (26 Oct 2011)

The pipework and tank should always be insulated. But in extreme cases, like we have seen over the last couple of winters, insulated pipes can still freeze, so one of these heaters used in addition to insulation should see you safe.
Leo


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## pudds (26 Oct 2011)

*Trap Door Insulation*

Is it still recommended that you insulate the trap door.

I was thinking of glueing 2" polystyrene board to this.

Its hinged downwards for ladder use, so some air would enter via edges as it was a d.i.y job but best I could do!


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## onq (26 Oct 2011)

Leo,

That's a great idea.

You have given us the price and the name, do you have the link to complete the set?


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## dewdrop (26 Oct 2011)

Thanks Ong. Plenty of food for thought!


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## Shane007 (26 Oct 2011)

Leo said:


> The pipework and tank should always be insulated. But in extreme cases, like we have seen over the last couple of winters, insulated pipes can still freeze, so one of these heaters used in addition to insulation should see you safe.
> Leo


 
This is true but usually because installers use the incorrect dimension/thickness of insulation on pipework. The normal but incorrect insulation I come across in attics is Tubolit 9mm thick (the thin grey stuff). The regulation requirement is equal thickness to the diameter of the pipe, for example, a 3/4" pipe should have minimum 19mm thickness or better and 1" pipe should have 25mm thickness or better. Tubolit do a 15mm thick for 1/2" pipes, 19mm for 3/4" pipes and 28mm thick for 1" pipes.

Another mistake is pipe joints are not lagged and the best insulation in the world on pipework will not stop an uninsulated joint from freezing. I use either normally thick lagging wrapped around joints completely sealed with tape or alternatively, Armacell sell a sticky back roll of insulation tape in 15m rolls. Effective but very expensive.

For tanks, I prefer to use rigid board polyiso bought in 8' x 4' sheets cut to 8' x 2' or 4' x 2' sheets to get into the attic. Form an insulated box around the tank pinning each sheet together with V's formed from wire clothes hangers. Vent pipes are brought through the board and insulated with Tubolit. This will not only encapsulate the tank but all valves & the brass fittings surrounding the tank. Any insulation should also be removed from the underside of the tank.


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## Leo (27 Oct 2011)

onq said:


> You have given us the price and the name, do you have the link to complete the set?


 
Sure, TJ O'Mahony have these listed in their current brochure for €15 each.

Many other builders providers will stock these also. Just beware the suppliers taking advantage of the current fear levels to sell these for €60/70+!
Leo


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## roker (27 Oct 2011)

One thing not mentioned, if you open the trap door to warm the attic, you will get condensation because the warm air from the house carries moisture which will condense when cooled


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## RugbyBoy (27 Oct 2011)

Hi All,

anybody used pipe heat tape like this 
http://www.tlc-direct.co.uk/Products/BNPW01.html

RB


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## onq (27 Oct 2011)

roker said:


> One thing not mentioned, if you open the trap door to warm the attic, you will get condensation because the warm air from the house carries moisture which will condense when cooled



Absolutely, because any vapour check at ceiling level is wholly by-passed.

I wonder is this one of the reasons why we had reports of condensation in attics last Winter?


ONQ.

[broken link removed]

All advice on AAM is remote from the situation and cannot be relied upon                                              as a defence or support -  in     and    of        itself  -         should       legal         action        be           taken.
Competent legal and building professionals should be asked to advise in                                              Real Life with rights to     inspect     and       issue         reports    on     the         matter     at  hand.


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