Is this dry rot

[Doug71]

A few years ago I was asked to go and look at replacing some rotten floorboards in a large bungalow, when I saw the boards I suspected it was dry rot. It was obviously a suspended timber floor so I took up boards in a few different rooms to check it out and found the strands and spores everywhere, under the floor and around the joist, it looked like something out of a sci-fi movie. I politely said it wasn't a job for me and left.

A couple of years later (as often happens) the large bungalow had gone and been replaced by four houses, probably the best thing for it I thought.

Every time I pass the houses I wonder if any of the rubble from the demolished bungalow was used as hardcore in the new builds and if the dry rot is still doing it's thing somewhere

 

[Bingy man]

Sounds like that awful Japanese knot weed , I will be checking all floors but the room in question is a suspended floor but it’s isolated all round by a solid floor bathroom and a solid floor hallway- after what I’ve learned about dry rot off this thread the entire floor boards in this room will be sent to the bonfire.

 

[Phil Pascoe]

At least you can eat japanese knotweed.

 

[Bingy man]

I’ve heard this but it’s not going to be on my plate anytime soon- the vegans can have it

 

[Pineapple]

Sounds like that awful Japanese knot weed , I will be checking all floors but the room in question is a suspended floor but it’s isolated all round by a solid floor bathroom and a solid floor hallway- after what I’ve learned about dry rot off this thread the entire floor boards in this room will be sent to the bonfire.

You are doing the right thing with the Bonfire ! - The Best Way to Sterilise the Brickwork is with a Blowtorch ! - When I took a City & Guilds Course in 1979 I was told that the local council can take you to court for Transporting Any Material Containing Dry Rot to Anywhere; even the Council Tip don't want it ! - Apparently Building Regs. Demand that All infected material is Burned On Site. - So you can tell any stroppy neighbours to shut up... Your fire is Protecting their property from wind-borne Spores. - (Wear a mask & gloves when handling the stuff and put them on the bonfire along with the rest.)

 

[Pineapple]

At least you can eat japanese knotweed.

https://www.wildwalks-southwest.co.uk/eating-japanese-knotweed/

 

[Rewound]

You are doing the right thing with the Bonfire ! - The Best Way to Sterilise the Brickwork is with a Blowtorch ! - When I took a City & Guilds Course in 1979 I was told that the local council can take you to court for Transporting Any Material Containing Dry Rot to Anywhere; even the Council Tip don't want it ! - Apparently Building Regs. Demand that All infected material is Burned On Site. - So you can tell any stroppy neighbours to shut up... Your fire is Protecting their property from wind-borne Spores. - (Wear a mask & gloves when handling the stuff and put them on the bonfire along with the rest.)

even though some people seem to put it on a par with nuclear waste. It isn't. Yes, under some very specific circumstances it can do a lot of damage to wood, (I have much personal experience of it) But apart from that i wouldn't worry about the stuff. Get rid of the source of dampness and it soons dies. As for it being dangerous to human health ? more so than any other fungus ? I wouldn't eat it or breath the dust of it in an enclosed space, but apart from that is it any more dangerous than a walk in the woods?

 

[Bingy man]

even though some people seem to put it on a par with nuclear waste. It isn't. Yes, under some very specific circumstances it can do a lot of damage to wood, (I have much personal experience of it) But apart from that i wouldn't worry about the stuff. Get rid of the source of dampness and it soons dies. As for it being dangerous to human health ? more so than any other fungus ? I wouldn't eat it or breath the dust of it in an enclosed space, but apart from that is it any more dangerous than a walk in the woods?

Thanks for your advice and yes mask and gloves and a forensic suit will all be burned With the rest - again I didn’t know about the blowtorch on the brickwork - good tip - any particular length of time or just played along the brickwork for a few seconds or a minute or two?

 

[Bingy man]

You are doing the right thing with the Bonfire ! - The Best Way to Sterilise the Brickwork is with a Blowtorch ! - When I took a City & Guilds Course in 1979 I was told that the local council can take you to court for Transporting Any Material Containing Dry Rot to Anywhere; even the Council Tip don't want it ! - Apparently Building Regs. Demand that All infected material is Burned On Site. - So you can tell any stroppy neighbours to shut up... Your fire is Protecting their property from wind-borne Spores. - (Wear a mask & gloves when handling the stuff and put them on the bonfire along with the rest.)

Super advice thanks for posting and sharing your experience and knowledge.

 

[Pineapple]

Thanks for your advice and yes mask and gloves and a forensic suit will all be burned With the rest - again I didn’t know about the blowtorch on the brickwork - good tip - any particular length of time or just played along the brickwork for a few seconds or a minute or two?

The Carpentry & Joinery Instructors told us that it's necessary to "Heat The Bricks As Much As You Can" - so just a quick flaming isn't enough.
They told us that dry-rot fungus & spores can only survive when the moisture-level "Exceeds 18%"
The purpose of the Blowtorch is to Dry-Out the Brickwork Completely.
Strange As It Seems, Dry-Rot, Like All Fungi - Needs Moisture & Oxygen To Live !
Once the brickwork is dry enough, it's a good idea to Seal it with a good Damp-Proofing Agent
40 -50 years ago, Bitumen or Silicone Liquid was recommended...FURTHER READING = https://www.rentokil.co.uk/dry-rot/

 

[Bingy man]

The Carpentry & Joinery Instructors told us that it's necessary to "Heat The Bricks As Much As You Can" - so just a quick flaming isn't enough.
They told us that dry-rot fungus & spores can only survive when the moisture-level "Exceeds 18%"
The purpose of the Blowtorch is to Dry-Out the Brickwork Completely.
Strange As It Seems, Dry-Rot, Like All Fungi - Needs Moisture & Oxygen To Live !
Once the brickwork is dry enough, it's a good idea to Seal it with a good Damp-Proofing Agent
40 -50 years ago, Bitumen or Silicone Liquid was recommended...FURTHER READING = https://www.rentokil.co.uk/dry-rot/

I’ve just got home but will digest this info as soon as I’ve had a rest thanks again for sharing it . Again I’m amazed at the wealth of knowledge I’ve gained from this forum and I hope it goes on forever.

 

[Richard_C]

3 things to entertain you this weekend

Plant/fungus???

You can all be right - it's an age thing. Classical Linnean taxonomy of living organisms now starts with 5 top level "Kingdoms": plants, animals, fungi, protista (simple multi cells like algae) and monera (even more simple, blue green algae, bacteria etc), BUT when I was studying a biology degree back in 1970 there were only 2 kingdoms, plants and animals with fungi and the others as sub-divisions of plants. (back then, there were 4 divisions in the national football league, rationally called 1,2,3 and 4. Now they have all sorts, I think 1 might be 'old 3' .... hard to keep up). Main thing though, if you are of a certain age you knew that fungi were a division of the plant kingdom not a kingdom in its own right as it is now. So, like I said, you can all be right.

A bonfire.

(an aside). My son lived with a friend in a rented bungalow near Watford for a couple of years. Estate built post war, long narrow back garden which shared a fence with an equally long narrow back garden belonging to a house in another street. He had observed that the owners never seemed to finish anything properly, ladders up against the gutters, dormer window frame taken out then left for months, things like that. There was a shed midway down that garden. One evening he was looking out of the kitchen window and saw the shed ablaze - proper flames and smoke - so he went round the corner and rang the doorbell. Oh, that's Ok said the houseowner all cheerful, we are getting a new shed and that one was full of junk so I put some petrol round the bottom and set light to it.

Dry rot.

Yes, its dry rot. Lovely 'textbook quality' example. Our first house, brick semi built 1920 ish, suspended floor, had dry rot at one end and wet rot at the other. If its very wet you get wet rot, you need some moisture for dry rot but it can't live if its too wet. Previous owner had concreted the driveway up the side, I found some airbricks that had been completely covered up plus rain ran towards the house. Grrrr. I knew little about property then, and the building society survey said nothing - if fact it said one slate was loose on the front elevation and didn't spot the missing slates on the back. I reckon they just drove up outside, looked out of their car window and wrote a report. Double Grrrr.

From memory though, dry rot has a failry distinctive sweetish rottingy smell which once sniffed is not forgotten. Maybe a good clue when searching for it?

 

[Bingy man]

I guess my next question is given the fact that it is a suspended floor what is the recommended procedure to stop the damp coming through the sub floor . What I can confirm is that there is in places quite a lot of rubbish and debris built up under the boards which seems to have been left by previous builders in their attempts to repair the walls etc . My own common sense is saying this must be removed to allow a good airflow through the building, the external vents are now clear and the overgrown garden ( brambles/nettles and even more rubbish) has been cleared. So my main question is what to do to prevent this from happening again as the owner is spending £££££££ renovating. Is it as simple as laying a dpm down - the floor has walls at certain points with staggered brickwork to allow airflow across the entire floor and support the longer joists so not possible to fit a dpm in one complete piece. As usual any advice on this matter is welcome.

 

[Richard_C]

Digging deep into memory banks here. 40 years since we left it. That first house (see above) was very nice to live in, room sizes, proportions, window and light positions and so on but turned out to be spectacularly badly built. 7 years of one thing after another. I think the 1920's were free of most regulation, as long as it didn't fall down before the builder sold it all was well. Why not save cement by a super-weak mix, gravity will keep the bricks together ..... We did find out why the house next door up the road was an odd detatched in a cul de sac full of semis - the pair of semis it replaced were hit by a bomb in 1940/41. Possibly the allotments at the end of the road looked a bit like nearby Ringway airfield.

We had to move (for work) before we sold it - employer paid a bridging loan which was nice - so it was empty for about 5 months over winter. It did start to deteriorate a bit despite regular visits - felt cold and damp - so maybe older properties need to be lived in and used more than newer ones just to keep the air moving and sort of 'breathe'. We only uncovered the true extent of the rot just before we sold, so declared it, knocked the price down and sold to a local builder. Never saw how he fixed it.

Anyway, yes to as much airflow as you can get, the bare earth beneath the suspended floor might be damp but shouldn't be full of puddles so where does the rainwater go, dowmpipes etc all working properly. Drains even. Ours was single skin walls, no cavity or anything, and I think the joist ends rested on bits of slate rather than bare brick, (dpc before flexible dpc was invented?).

Depending on age of house and what alterations might have been made in and around it, probably best thing is to sit quietly and have a good look and long careful think - the best solution won't be the same for all houses.

Anyway, I can do the biology but not the building stuff so hopefully someone will be along with some proper ideas.

 

[MikeJhn]

The only way to eradicate this problem and prevent it occurring again is to bite the bullet and take up the whole floor, liberally spray the walls, dig down until there is sufficient space to lay a DPM and oversight of concrete/Lytag, build new honeycomb sleeper walls and re-place, joists, floorboards etc, anything else is folly.

 

[Rewound]

And yet you called it a plant twice.
Living organism is a bit of a wide umbrella, just call it a fungus.

But anyway, after the last time a question was raised about dry rot, I found a really good video by Dr. Ridout on the subject after you mentioned him. I think it answers a lot of the questions people might ask about rot in general.

what an excellent video, helps to dispel the irrational fear that surrounds dry rot. In many cases just getting rid of the source of dampness could be all that is needed.