Wooden finishes in unheated house - advice

[frediaz]

I was debating with the people in the plumbing section about a house I have unoccupied and I wanted to empty the heating system instead of letting it come on when the temperature drops below 5 deg but there was the question of damage to wooden stairs, floors and doors.

The house was built recently and completed at the end of 2009. Then the heating operated during last winter sometimes, to protect it from frost and finish drying the plaster, etc. The house has never been lived in and it is well sealed so nobody has been there to generate humidity. I could even get a humidity meter to check. So I consider that it is not in danger of damaging the wooden finishes. Have I got a point?

 

[^woody^]

The varying temperature will create varying humidity, and any timber (whether coated or bare) will be affected - typically absorbing more moisture from colder air. The fact that the property is "well sealed" is irrelevant to internal humidity

This won't cause damage in itself, but any rapid drying when the house becomes occupied (or a hot few spring days) can lead to timber shrinking and the associated cracking, splitting, squeaking, paint blistering and plasterboard nail popping.

Similar thing for the water or heating pipes when they get used after being cold and the joints get stressed

 

[ladylola]

Agree with woody there. I've seen jobs that have been finished , look loverly, and the owners come in and wap the heating up full and then start moanimg when cracks and shacks start appearing.
Leaving the heating off won't in itsself cause any damage as long as it's return to normal as slowly as possible.

 

[frediaz]

Yes, I agree that any temperature shock can cause damage to almost anything, but I would be surprised to see damage to the pipework as most people do not start the heating until the ambient temperature is around 17 deg then there is water at 50deg or so suddenly going through the system. Even worse, people who go to their cottage (in France or somewhere) during the skiing season will be starting the heating at ambient temperatures below zero and then raising the temperature in the system 50-60 deg above in a few minutes.

I also agree that it will be better to increase the temperature gradually but that will happen naturally during the spring if the house is unoccupied (and the heating unused) during the winter.

 

[^woody^]

A sudden warm spring day can increase temperatures suddenly within a few hours and cool again just as quick later in the day. Plus, this temperature difference will normally be just on one part of the property, or just the bits where the sun shines through the window

This means that temperatures do not gradually increase/decrease, but do so in big steps and quite quickly, and associated humidity from the heating cooling is not even either.

Same thing with the pipework. A pipes in a property where heating comes on and off do have some latent heat from the ambient air and so the increase is not that suden. Cold empty pipes, filled with very cold water and then heated do get greater stress. OK, the pipe and joints may cope with this, but the greater stress means that it is more of a risk for any weak joints or fitting

Its fine if you can be sure of gradual stepped increases in temperature and decreases in humidity over many days or a few weeks. But in reality this is not possible, so the risk increases