To heat holiday home or not?

[Musicmonkey<ADDRESS><STRONG>Musicmonkey<STRONG><ADDRESS>]

Since we bought our old stone house we have suffered from damp in the lounge.  We had the house surveyed and are assured it's not rising damp but condensation.  We have taken some steps to combat the problem.  Firstly, we installed a false wall with a cavity on one side of room (internal wall).  Secondly, we had a mechanical ventilation unit fitted with vents in the bathroom, loo, lounge and kitchen.  This runs continuously and is turned up after steamy showers, cooking etc.  The windows also have those little vents.  Last winter the house was heated for a couple of hours each day and windows were opened when sunny, but we are still experiencing damp.

We have recently invested in a dehumidifier and feel it would be prudent not to heat the house while empty as the rising and falling of temperatures would cause an increase in any condensation. 

What do you think? 

PS.  Our French neighbour, who claims to know about these things, says we should paint a special product on the outside of the wall to prevent moisture coming in.  If the problem is indeed condensation, surely this would make matters worse by closing in the moisture? However, is it likely to be condensation if we have all these vents removing air and presumably circulating the air?

Please help.......confused.

[Dick Smith]

I've just been looking at slow heaters (I'm thinking of building a big shed/workshop in the UK) and there are a number of products available, cheap to buy and cheap to run, including a frost-activated one. All under £30! The company was Lyco (www.lyco.co.uk)

[0Helen]

When we first bought our old house it was very damp and some of the plaster in one corner of a downstairs room was very wet.   We did simple things to  rectify the problem.   We removed soil and plants from near the outside walls.   We killed the moss using dilute ammonia and pressure washed.  We lit the fire and aired the house out every chance we got.  The cellar had a pool of water in it so we cut holes in the door and fitted ventilation grids and a concrete threshfoot so heavy rain did not enter.   It does take some time for old thick walls to dry out and we no longer arrive to find a thick fur of mould on anything that holds moisture.  In the future we intend to fit a ventilation system.

Hope this helps.

[Piprob]

I think Dick and Helen are right.

You might be surpised to know just how much moisture the fabric of a house is absorbing and giving off all the time. Perhaps it doesn't need saying, but this 'breathing' is particularly so with unsealed materials, stone, brick, wood, etc., and with floors laid without a damp proof membraine separating them from the soil beneath. It takes a long time to 'dry-out' a building that has not been regularly occupied, and an unheated and unventillated property will start to re-absorb moisture the minute you leave it empty.

There is no general or single solution, (more so if the damp is a consequence of delapidation or defect) except regular occupation with regular air circulation and warmth.

 

[Mpprh]

hi

I think this is a long process.

I have stone walls that were flooded in Sept 2002 and they are still not 100% dry.

So far, I'm relying on natural breathing.

Peter

[Hereford]

When we bought our property, for renovation, we had one damp corner.  Our architect told us it would dry out at the rate of one inch per month. For thick stone walls this can be quite a time!

We had electric heating installed and until we moved over permanently left them on "frost guard" setting all winter.  We have had no damp problems since.

 

Hereford

[ClaraQ]

We now don't bother to heat our stone house during the winter months as the rise and fall in temperatures seemed to cause more problems with mold and damp spots. 

Since we invested in a mid-range dehumidifier, the problem seems to be solved.  We sit it on a small table above ground level and leave it on a timer to come on every night with the extracted water draining into our ground floor shower.  One weekend we left it to drain into a bucket to see how much moisture it actually extracted.  Big mistake!! We were away for 3 nights and the bucket was overflowing on our return.

Clara

[Musicmonkey<ADDRESS><STRONG>Musicmonkey<STRONG><ADDRESS>]

Thank you very much for sharing your experiences.  Am I correct then in deducing from the above comments that:-

1. We must be patient for the dehumidifier to work its magic and

2. We should gently heat the property during the winter months when its not occupied?

Does anyone share our thoughts/concerns that heating the inside will produce more condensation on the walls which will of course be cold?  That is after all how condensation works isn't it?

Edit:  Clara's message hit the site while I was composing the above.

[Clarkkent]

[quote]Thank you very much for sharing your experiences. Am I correct then in deducing from the above comments that:- 1. We must be patient for the dehumidifier to work its magic and 2. We should gen...[/quote]

If you plan to leave the heating on while you are not there then you should check that this will not invalidate your insurance.

I used to find that the inside of north facing walls would get very wet during my winter absence. I eventually cured it by leaving windows secured open (about an inch) behind shutters and allowing air to circulate throughout the house.