Damp in new house purchase

[MatthewC]

Could we (aka you lot) compile a list of disingenuous questions to ask tradesmen and 'experts' to test their probity and understanding of old properties?

I think my best general question for that would be "Would your recommendations be the same if my 200 year old building was twenty years old?" If the answer is "Yes" then he gets elbowed fast.

 

[Feltwell]

Agreed - waiting a while might be sensible but the house needs rewiring and replumbing as well as a new kitchen and bathroom (which might have to wait for a lack of pennies) and we thought it would be sensible to get all the messy stuff done before moving in. After that there is a lot of stuff that is probably more cosmetic that we thought we could fix in time (whilst living there).
Cheers
Mark

I am generally in favour of the "move in and give it a while before making changes" approach, having made a few changes to this place in the early days that I now regret - but - a rewire and replumb is an exception to me and is something I would get done before you move in if at all possible.

It's a total pain in the @rse trying to do those jobs whilst you're living in the house - especially with a rewire where every room gets disrupted. Yes, if you live in the house first you will make less mistakes - I can guarantee if you get it done before you move in then you'll find that you want an extra socket here, that socket is hidden by a piece of furniture that takes up a bit more room than you thought it would, that kind of thing. However, they are fairly easy things to fix with minimal disruption to the rest of the house as you decorate each room.

An empty house is so much easier to work on - no furniture to move, no carpets to take up, no need to make it habitable again at the end of each day. Just plan everything in advance as thoroughly as you possibly can - and if in doubt, put it in anyway. Not sure if you'll want an electric shower in that bathroom? Run the cable from the consumer unit anyway - it doesn't cost that much - and leave it coiled up at both ends and labelled underneath the floor, so you can get at it easily - or ignore it - when you come to revamp that bathroom. Don't forget telephone extensions, alarm systems and data cabling - I fitted the first 2 before I moved in and now regret not doing the data - it would have been so easy to do it at the same time

Most other jobs that you'll do in the house affect 1 room only at at time, unless they are structural. Especially with kids around, having only one room that is uninhabitable / hazardous to enter at a time is a major advantage!

You'll also note this is contradictory to what others have posted above, we don't always agree! :wink: No rights or wrongs, only opinions.........

 

[MdB]

Penners, I've always had difficulty getting my head around this, my understanding of the science and my experience of the practice seem to be at odds!

Last winter, during the long cold dry period, RH levels dropped to about 40% in some rooms in the house. In summer, with the windows open, it is never below about 75%. It is during the summer that doors swell and stick. Obviously the CH is on through the winter and not in the summer, which is a contributory factor. So if the RH is up and the wood is swelling, what does that mean in terms of damp in the walls? There should be no condensation in summer (as there is no temperature differential), there may be better ventilation in summer (although the forced draft through the Rayburn must suck huge volumes of damp air out of the kitchen in winter), but in terms of difference in moisture content between substrate and air, will this not be greatest in winter?

This made me think so my musings..

In Winter

Assumptions: Inside temperature 20 deg C, Outside temperature 5 deg C. Outside humidity 75%.

20 deg C air can hold three times the moisture that 5 deg C air can so outside air brought inside and heated will have a humidity level of 25%. This will be very good for removing moisture from the inside of the house. However, ventilation to allow this to happen will cause large amounts of heat loss so to keep heating costs sensible, windows / doors are kept shut which keeps the moisture inside.

Moisture in the walls will mainly evaporate from the inside face due to the high humidity outside and because any moisture moving from inside to out will cool and condense as it moves through the wall.

In Summer

Assumptions: Inside and outside temperature 20 deg C. Humidity 75%.

Airflow through the house in summer is likely to be far higher than in winter so moisture picked up in the house will be quickly transported outside. However, as the incoming air already contains a large amount of moisture, this isn't going to be as good as in winter.

Moisture in the walls will evaporate from both the inside and outside face though reduced on the inside due to the higher moisture level. The outside will dry very quickly due to the very large airflow.


Just my thoughts - there are probably all sorts of mistakes in there.

 

[Penners]

Summer isn't far away, so you have a wonderful opportunity to let nature do a great deal of the work for you. Remember that warm air can hold more moisture than cold air, so a combination of warmth and ventilation will do a world of good in reducing the overall dampness of the house.

Penners, I've always had difficulty getting my head around this, my understanding of the science and my experience of the practice seem to be at odds!

Last winter, during the long cold dry period, RH levels dropped to about 40% in some rooms in the house. In summer, with the windows open, it is never below about 75%. It is during the summer that doors swell and stick. Obviously the CH is on through the winter and not in the summer, which is a contributory factor. So if the RH is up and the wood is swelling, what does that mean in terms of damp in the walls? There should be no condensation in summer (as there is no temperature differential), there may be better ventilation in summer (although the forced draft through the Rayburn must suck huge volumes of damp air out of the kitchen in winter), but in terms of difference in moisture content between substrate and air, will this not be greatest in winter?

Worms, MdB has written a much more learned exposition on this subject, above, than I ever could. My simplistic view just leads me to believe (in an amateurish way) that the most significant factor is the movement of warm air through the house. In winter we keep all doors and windows tightly closed (particularly if we [ie: you] live near the Arctic Circle!). So the air in the house gets rapidly saturated and moisture loss from damp walls drops away to near zero. And any fresh air that enters the house is cold anyway, tending to reduce the temperature of the ambient air (hence it's moisture-holding capacity).

In summer, we throw open the doors and windows and allow warmer air to blow through the house (well, down here in temperate climes we do, anyway!). So the air against the damp wall is constantly being renewed, and doesn't get saturated. So drying out can continue uninterrupted.

I imagine that schoolboy view of things is probably shot full of scientific errors. But in my personal experience dampness dries out significantly more quickly and effectively in summer than in winter. QED.

 

[CatherineB]

Hello Mark, and welcome!

There are at least a couple of other dads to new babies on the forum (Wobs and Robgil), so you won't be alone in your early-hours meanderings on the forum once you get going.

This is a very friendly place, with lots of chat, some useful information, cyber-tea and kit kats (other snacks are available) and not a few chickens - enjoy!

 

[Penners]

kit kats

Ooh - I want one now...

 

[FamilyWiggs]

This is a very friendly place, with lots of chat, some useful information

Steady on Catherine, we don't want to raise expectations too high. 8)

 

[Penners]

What you don't realise, FW, is that we all have lots of friendly chats while you're out doing that new thing you do... what's it called... "running". :roll:

 

[FamilyWiggs]

I know DP - but I just can't fnd enough time to catch up on all the threads...

 

[JoceAndChris]

Just on the subject of how to go about your house project, surely it's entirely dependent on your final vision, and budget. We all love our houses completely, but it isn't always possible to sort them all at once. As for rewiring, replumbing, replastering before moving in, that would require a large pot of cash on moving. We came here with terrific debt due to not selling our previous home and the company Chris worked for folding, so such things just weren't an option.
Although it can feel frustratingly slow, our one room a year approach is working. The mess is confined to just one room, and money can be lavished upon it for everything - sorting out the plaster, the rewiring and fitting of lights and sockets ( that alone is going to be £2500 for our dining room!) getting the missing bits for the fireplaces, repainting, wallpaper, floor waxing, furnishing, curtainry.
We won't get to the bathroom until 2015.
The scale of what changes you wish to make and how much money is immediately available defines approach, but I worry that arriving somewhere with a big vision and a big pot of cash is most often responsible for ruination of old properties - loss of historic features, inappropriate damp remedies, decisions on design and usage of rooms that come to be regretted. There's a lot to be said for a very slow, cautious approach if the house has a lot of old and interesting fabric, or even if it doesn't.
The same is true of the garden. I read something this week in BBC gardens that really struck a chord "We wasted too much time working too hard before we really knew what we wanted". Now there is the best reason to put your feet up and read design books you're likely to find.
I wish the OP lots of luck with the house project though, and echo the great advice given regarding damp.

 

[skier-hughes]

We won't get to the bathroom until 2015.

BEAT YOU, I'm doing my bathroom in 2011.............. ok probably 2012 and 2013 the rate I work, but I'm hoping to have it done by Easter!

 

[Moo]

I agree with you, Joce, about the one-room-at-a-time approach, but am not so sure of its feasibility when it comes to things like re-wiring and installing central heating.

 

[Feltwell]

We won't get to the bathroom until 2015.

I'll stay upwind then.... :wink:

the rewiring and fitting of lights and sockets ( that alone is going to be £2500 for our dining room!)

:shock: What on earth are you fitting? The light fittings must surely be the bulk of that, and must be very extravagant!

Just be careful with the "one room at at time" approach with wiring - the problem is that sorting the wiring for one room can sometimes involve disrupting the decoration in another room, same goes for plumbing.

Pros and cons to all approaches. If the wiring is unsafe though the OP may have little choice, and a rewire in one go in an empty property will be cheaper than a room-by-room job in an occupied property.

We definitely suffer with the "working too hard before we really knew what we wanted" syndrome with the garden. Problem is, we still don't really know what we want - we just know that we don't like what we have now!

 

[JoceAndChris]

Oh, poor Feltwell. If you go to the local charity shops with a tenner in your pocket you can stock up on umpteen books of garden design.

 

[Feltwell]

So you don't fancy Ikea light fittings then?

You're quite right, I missed the ceiling - that's a big cost but sounds very worthwhile.

I have umpteen books on garden design already, but lack much in the way of vision on that one, and, if I'm being brutally honest, interest at the moment. I like looking at nice plants and gardens but have too much on my plate with house & family as it is. It will probably get left until the kids are a bit older and any design does not need to incorporate a whacking great trampoline, a wendy house, a slide, swings under the old apple tree and all the other toys! The garden is a reasnoble size but not that big, they take up quite a bit of the available space, especially the trampoline.

What we are going to try and do though in the shorter term is at least take out all the inappropriate trees (previous owners liked planting them 12" from fences :roll: - doesn't always please the neighbours), put a couple of new trees in and get some hedging started, so by the time we get to do the garden more thoroughly they will have had a chance to establish.

 

[Penners]

Just be careful with the "one room at at time" approach with wiring - the problem is that sorting the wiring for one room can sometimes involve disrupting the decoration in another room, same goes for plumbing.

I agree. Those two services really need a whole-house plan, otherwise they can become expensive in specialist labour and, unless you're extremely forward-looking, need later modification (which of course adds to the cost).

I'm sure Joce will have these problems well thought through, but you do need to be aware of the risks.

In particular, be very careful abut planning your electric points. Don't economise on the number of sockets that you install - you'll always need more than you thought. And remember the fundamental law of nature: no matter how carefully you plan the location of your sockets, you'll always end up with at least one behind the chest-of-drawers. :wink:

 

[JoceAndChris]

Ikea and I parted company forever in 2001, with a ceremonial burning of their papier mache coffee table - ugh. I actually prefer B&Q to Ikea, by miles.
Anyway, your plan for the garden sounds good, and I can relate to the impossibility of even thinking about it with so much else on.

 

[FamilyWiggs]

but I'm hoping to have it done by Easter!

Steady on Graham, we've talked about this before. Mrs FamilyWiggs occasionally reads these pages! :shock: Easter is only 4 days long!

If you really must be specific about when a project will be completed, then I find naming a season is usually precise enough. Try going with "Summer" and if really pushed, qualify it with "late" or "early".

 

[Feltwell]

In particular, be very careful abut planning your electric points. Don't economise on the number of sockets that you install - you'll always need more than you thought. And remember the fundamental law of nature: no matter how carefully you plan the location of your sockets, you'll always end up with at least one behind the chest-of-drawers. :wink:

Too true - I tend to work on the basis that if I put enough in then the odd one that ends up behind the chest of drawers doesn't matter much!

 

[Penners]

but I'm hoping to have it done by Easter!

Steady on Graham, we've talked about this before. Mrs FamilyWiggs occasionally reads these pages! :shock: Easter is only 4 days long!

Relax and look again, FW. Graham was cunningly vague about which Easter.