Mid-Terraced House - damp in bay window area & dining rm

[dazednotconfused]

Hi all,
This is a long one to explain im afraid! We have just bought a house which we need to move into next weekend. There was a damppatch of black mould under one corner of the underside of the carpet when i lifted it up to remove. The patch was also evident in the chipboard flooring directly under aswell, all lounge flooring is chipboard whilst the dining rm floor is original floorboards so somebody has obviously removed the lot due to rotten boards at some point (the lounge/dining rm has been knocked through by the way)

All floor joists measure dry when tested with a damp meter, so thats good! However there is a visible damp area of ground (soil i assume or rubble/cement type of base) around the bay window especially in one corner nearest the hallway/entrance. In fact all of the ground measures off-the-scale damp but this may well be normal as it is the ground after all! The house is victorian built in 190'something & has no DPC. We noticed the crazy paving laid directly outside the bay window was too high & so have taken it back down 2 courses to expose more bricks. Iam planning to put some loose pebbles down around the wall french drain kind of thing.The bricks have been painted from top to bottom of the front projection & the house is rendered on the back. The pointing under the front window is pretty deteriorated & there is a half brick missing for some reason sub crazy paving level. There are 2 air bicks at the front which were slighlty obstructed with a build up of rubble & dust, both at internal floor level. I have cleared these out. The airbrick at the back (dining room) is completely obstructed with bricks & is too low so the timber & the floor joist has rotted away over the years.
My question is do we carry on as we are now we have made some improvements to ventilation under the floor & hope that once the external wall has been shot-blasted & re-pointed & with gravel down that the problem is controlled, or do we need to look into installing a DPC or that chemical injection process which the 'damp expert' recommended when he came around.
Any ideas would be much appreciated! Thanks

 

[dazednotconfused]

Some photos of problem area are here: //www.diynot.com/network/dazednotconfused/albums/14361

 

[mikeey84]

the thing with damp is that any changes you make to the fabric of the building to remedy damp problems take a long while to show improvements. It sounds (in my limited) experiance that you have doen exactly the right things, and are planning on doing even more right things (pointing).

I would leave it after doing the pointing and see what difference it makes. Also have a look for any other sources of mositure such as:
-Radiator/water pipes
-Leaking guttering and lack of (we dont have guttering around our bay window)
Both of these could contribute to any damp issues. If not I would leave it for a while (maybe leave an access hole?)

 

[AlexaCollinsDesign]

Sounds like you're doing the right things, but I wouldn't rush to do the front wall until you're certain you've established the cause of the damp. A local damp/rot man could probably come and advise you and be worth spending the money.

I've done quite a few Victorian houses and the front bay is often a damp area. You said the air bricks had a build up of dust and rubble and that there was a brick missing. What sort of rubble was it and whereabouts?

This house is a hundred years old and things deteriorate over time, sometimes you get a build up inside the cavity of old mortar snots or stuff that over time builds up and so the cavity is breached and damp can travel from outside to in. I've even done refurbs where we've found old lead sashes in the cavity and once half a window! where the cowboys replacing the previous windows had just dropped or lost their rubbish the the cavity and couldn't be bothered to try and get it out. So it could be that the cavities need clearing.

 

[dann09]

daz... do you still require advice - looking at your pics and reading your post there are a number of items that need addressing?

I'd suggest, as a place to start, always posting damp issues in the building forum.