Condensation

youth_leader

Does anyone know how I find out about the water table please?  I've googled it and can only find reference to areas with coal mining.

tacpot12

This link is about the best that is publically available but it covers so few points that it is more or less useless: Groundwater level information | British Geological Survey (BGS)

The BGS have other data, but it can be costly to access and interpret. I would consult a local chartered surveyor as their local knowledge will probably be sufficient. You could always dig your own borehole (or pay a contractor to do this for you) if you need to know the level of the water table with any precision.

If your query relates to condensation, then rather than worry about where the water table is (which you can only affect by means of expensive drainage works), why not just ventilate the affected area?

Doozergirl

I'm interested to know what the whole problem is. This just sounds like one rather interesting theory being explored.  

knightstyle

When we bought our house I went to the water meter to take a reading and the hole was full of water and that was because of the groundwater level so that may be a starting point.

stuart45

The water table can vary even in the same area, so you can only get a rough idea before you dig out the foundations. 
A friend of mine built a brick well in his garden, which told him when the table was high. Interesting job, he used to dig under the bottom brick course and allow the brickwork to drop each time.

youth_leader

Thank you. The problem is the surveyor thinks that water is getting under my new 3 bedroom bungalow March 2021 purchase. The end half of the back bedroom/bathroom/lounge and kitchen floor are an extension, with a concrete floor.

I've only recently found out that in 2016 the vendor had the floorboards and joists replaced using chipboard in the two bedrooms, bathroom and hall due to the contractor (unfortunately no longer trading)  telling her she had woodworm.  No surveys unfortunately.  All of the chipboard and underlay on these floors is covered in thick black mould.  

The only room with floorboards, the largest front bedroom where I sleep, wasn't replaced.  The surveyor came in November, it has wet rot/dry rot and woodworm.

I've had the surveyor back again yesterday as I've cleared another bedroom.  He cut a hole in the chipboard, and said the joists were soaking, but luckily as they are new not rotten.  There are many airbricks all around the bungalow and all of them look clear. 

I have a choice of replacing all of the floors with timber with far more ventilation, or going fully concrete.  

stuart45

Do you know if there is a concrete oversite below the floor? It should be higher than ground level. If you have standing water under the floor for much of the year it can be a problem for timber floors.
Also if the sleeper walls aren't honeycombed it can affect the air flow.

youth_leader

Not sure stuart45.  The hole made to check the wet/dry rot etc was just a floorboard wide and when I looked under I could see solid brick pillars, the ground is mashed up grey concrete which seemed to be wet to the touch  I was looking as the surveyor had said to check to see if I could see water when it rained, hole wasn't big enough and I didn't want to enlarge it.  

stuart45

Sounds like you could have a high water table. The extension might have blocked off some of the air bricks. Putting in plastic ones in increases the air flow, although don't look so good. 
There must be a reason why this problem has occurred in recent years.

youth_leader

I agree, and will try to find out as it would make more sense to go concrete then.  The airbricks are plastic, and I have been checking them regularly to make sure they are clear. 

The surveyor did say the floor should have been ducted through the concrete to the subvoid. I've still got a bed in the back bedroom which is part concrete (had to move out when my flat roof was blown off) at the time he didn't want to cut through the chipboard floor in there. 

I'm just having a rest after having builders here for three weeks redoing my roof and kitchen/lounge ceiling. I'm ordering boxes, then packing and cramming everything into the concrete floor area.  I'll be glad when they've taken the floors up and I can find out where the water is coming from.  

stuart45

With air bricks it's best to have them in opposite walls so you get a good air flow. Solid sleeper walls will block this.