Built late 19thC Dry rot / damp / Exterior ground height / Drainage

[Matt Green]

As Matt said, at least the rot is fruiting, meaning we're making progress (he says!).

It's a good sign- it just tends to give folks a strong dose of The Fear. The fungus doesn't want to spend it's energy making those complicated structures to disperse spores if it is happily digesting your roof, it will stay in it's hyphal state as long as it can otherwise. Scrapers, wire brushes and surgical wood saws are your friends once the water ingress has been addressed.

 

[Matt Green]

Hoping now its gone with the skirting boards from lounge, bathroom and kitchen it'll slow things down a little and give me time to fix the guttering or would stripping the plaster now be an idea?

Stripping the plaster is only worthwhile if you suspect there are embedded timbers in the wall, otherwise it's inert and fungus is just growing around it. That waterproof membrane isn't does much for you though, other than reducing evaporation - that can go.

 

[bart]

Stripping the plaster is only worthwhile if you suspect there are embedded timbers in the wall, otherwise it's inert and fungus is just growing around it. That waterproof membrane isn't does much for you though, other than reducing evaporation - that can go.

Glad I'm on the right track matt, thanks again. The waterproof lined the lounge which seems an odd decision.

Now a little confused again as I attack the bathroom door frame (perhaps a little too vigorously as pictured) and found the rot doesn't seem to go much past the standard 1.5m and this is also true on the inside.

However found this (image2) strip at the top which is totally rotten yet everything surrounding it is fine. I understand the lounge ceiling was previously artexed and was removed by the previous owner and beams accordingly sandblasted.

I understand above this should be the oak lintel and my beep monitor reads 5-10%. What have I missed please? Ideally I'd like to leave the door frame (happy wife happy life) until water ingress is more adequately resolved.

 

[Matt Green]

Looks like a separate and very old outbreak. You could strip the paint and see what is going on, equally carefully knocking a square of plaster with a hammer and bolster out to expose the lintel bearings seems prudent.

 

[bart]

I would guess the high exterior ground levels will be much of the problem. Ideally you want the ground level outside to be a couple of bricks lower than inside and for the bricks to be exposed and pointed with lime. That lets any water coming up the wall evaporate away before it thinks about getting inside.

A French drain is good for surface water (until it gets blocked by soil) but will not allow evaporation from the wall and will be wet below the top layer of pebbles. An open trench would be a lot better: https://www.periodproperty.co.uk/forum/threads/the-zebcolm-trench.17575/

The masonry paint you have outside will be waterproof. That means no chance for water to evaporate away once it's in the wall so it is important to stop it from getting in.

Worthwhile sorting out rainwater drainage. If you hire a person with a digger a soakaway can be installed in a day.

I would forget damp firms as the problem should go away once you have sorted out the basics. For curiosity what is that wall in the third picture with damp all the way up?

Forgot to say - It's easy to spend money on experts when you first buy a house. It's lack of confidence and a familiarity with money spending during the buying process. It's your house and most stuff is simple. You can figure it out without experts.

Groundworkers seem keen on a gabian retaining wall and which would seem to provide far more water flow. I appreciate the limitations of aesthetics but wondered if anyone has tried this and whether it was effective in allowing water through and not under?