Fungi

drpepe said:

is the block paving over/close to the original damp proof course?

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ree said:

1. post a plan view of your house, a similar one to drpepe's - dont use his sketch its confusing, (perhaps remove the double post you've posted in another forum - thats confusing too).



2. Indicate where the air bricks are all around the house? Are any floors solid?
Air bricks indicated on diagram, only the kitchen floor is solid.

3. indicate the areas shown in the pics. Is this the area of the dry rot attack?
The pics indicate the hallway, kitchen side. The pics are of the outside hall wall.

Dry rot attack was in the lounge, the corner between the outside wall and kitchen wall collapsed.
Have you had damp and timber inspection and report?
Nope.

4. show where the block paving has been installed.
As shown in diagram in dotted lines, it goes all the way round the house.

5. pic a close up of your DPC - does it look or feel like bitumen?
It does is very brittle breaks very easily now.
Pic to come:

6. does the sand & cement plinth run around the house?
Just along the side of the house, kitchen /hall side.

7. Pics of the whole rear elevation and the whole front elevation please.
Pics to come:

8. a pic of the skirting and interior wall above where the floor collapsed.
Pic to come:
But nothing to see all joists, skirting, wall paper, floorboards, laminate flooring, underlay etc has been replaced by builder/joiner. All cleaned out of rubble and debris.

Cavity wall firm compensated us £250 for blocking air bricks with rock wool.. They said they put in sleeves so it don't happen again? I don't see any sleeves in the hallway air bricks although they did replace the air bricks even the one shown in the pics, but they failed to tell me it was blocked on the other side and facing a joist.

Builder put sleeves in the lounge for me though.

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ree said:

ref. item 1. thank you for the clear and prompt diagram, it truly helps.

2. you appear to have plenty of air bricks.
What & where are the sleeves in the lounge?
As much thro and cross ventilation as possible would be good.
The sleeves are just big tubes spanning the cavity so the air brick can't get blocked by falling debris. Not sure about cross ventilation as each room has its brickwork down under floor boards.. It's seems there have been some modifications in the hallway.. As the old wall bricks have been left in situ.. I am currently removing these to improve cross ventilation in the hall.

3a. In the lounge corner, would it be too impractical to lift a board or two and pic the dry rot area below the floor?
It sure would..
Were all the affected joists removed or cut back?
They were replaced.
Were new joists "end-capped" with DPC material?
I hope so, I know pressure treated wood was used.
Was the whole area chemically treated?
Yes with some anti fungi stuff, not sure what.
Was all cellulose debris removed?
Not sure what you mean by cellulose, but I'm told all rubbish was removed.
Was the joiner/builder experienced in Remedial Work?
Don't know? What is remedial work?
How would you know?
I don't?
Did he extend his investigation for dry rot well beyond the immediate collapsed area?
I do t know? That is what I'm doing now, I was only supposed to repaper the hall, but looks like I'm doing everything.
Were affected skirting and plaster removed and the walls chemically treated?
Yes plaster and new skirtings fitted, I presume the wall were treated.

3b. All joist tails that rest in pockets in your walls are at risk of wet rot (at least).
I know, that's why I have the hall floor up, there has been a musty smell for a while.. Im currently putting the floor right, dpc missing to protect joists.. Leveling etc.. IT really needs to dry out in there I'm still pulling soil and rubble out..

I have to go now but i'll be back this evening.

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ree said:

3c. can you lift a board at the front diner wall to examine the joist tails in the front elevation sub-area?
I'm afraid not as half the hallway furniture is in there at present.. That will be my next job when the hallway is done.. One job at a time. I will have a look through the air holes hallway to front lounge to see what's in the other room is I can.

4. the block pavement is obviously too high and bridging the outer skin DPC but unless the cavity is full & bridging above the DPC then rising or penetrating damp cannot cross to the inner skin.
If the cavity is "full" then it must be opened and cleaned out. Cavity pics please.
There may well be bridging in the cavities there is a lot of rubble and soil coming out of the parts I have access too.. I am doing my best to remove what I can?




FWIW: i cant see any loose insulation beads in the previous pics?
I don't know what you mean? You mean cavity wall insulation? I can't see much either? Another shoddy job? This is turning into the house of shoddy jobs.. It most probably didn't get in every part of the cavities. Due to being blocked with debris or another cowboy installer

5. The bitumen DPC's should be pefectly adequate for purpose.
Can it fail over time?

6. the plinth is bridging the outer skin DPC and was perhaps installed as a remedial measure.

What kind of remedial measure... Im not 100% certain but I think there were a lot of blow bricks now covered by the plinth?

7. pic of the side elevation please.

Side elevation:


Front elevation left to right:


9. pressure treated joists are not enough - they should be lathered with remedial "mayonnaise" and capped. Backs of skirtings should also be lathered.
I hope they were...

10. thro ventilation is needed between the hall and the diner, and between the diner and the lounge.
Hall and front lounge has ventilation not sure about front lounge to dinner though.. I've never been under there.

11. Do you have chmney breast's - are they blocked?
I do, front lounge has been blocked off. Dinner still has a working gas fire place.

12. has your neighbour complained of any damp difficulties, or a musty smell etc?
I don't know will enquire.

13. you could carefully examine all the skirtings and lower walls in the house.
They all seem ok no signs of any horrors

14. there's not much to do or see in the kitchen - look in and behind units and appliances and minutely examine the wall and floor junction with the wall thats had the dry rot work done.
There was rot on the skirting in the kitchen, I ripped the affected parts off and waited to see if it got worse. It didn't and has now dryed out. I knocked it back to the brick just to be sure.. The builder/joiner obviously didn't check this.. Another cowboy.




- perhaps google unfamiliar terms?

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ree said:

3c. joist tails resting in bays and chimney breast recesses are the most vulnerable to fungal attack.
You seem to have reasonable air brick ventilation at the front elev. altho i cant see an air brick on the front face of the bay?
There is one on the front bay, 3 in total on front evaluation.
There's also quite a bit of efflorescence to be seen on the front elev - why?
I don't think it's efflorescence, some of the faces of the bricks have blown, I don't know why they were like that we we moved in 30 years ago. We had the front elevation repointed, I think k it's the residual white mortar that's embedded in the blown brick faces.
The raised front step is bridging the DPC, and possibly blocking air vents below the door cill?
There's no air vent there but I see your point about dpc bridging. I will see if I can get any dpc between the step and wall.

4. as you have probably realised, you will have to open up the inner wall skin to reach into the cavities.
But all debris must be lowered below the DPC level. Knock down any snots you see clinging to cavity ties.
Sometimes its necessary to open up the cavity from the outside. Done carefully, all the bricks can be preserved and replaced.

4c. yes cavity wall insulation beads - they are blown in, and the blow holes can usually be seen in a regular pattern on the outside elevations.
Yes we have the holes and there is rock wool blown in, we don't have beads.

5. Your bitumen DPC is long lasting - dont disturb it. Opening up to gain access to the cavity dont lift the brick course immediately above the DPC.

6. Retro plinths were typically added as a mistaken remedial measure after discovery of damp in the house or to cover blown bricks. They typically can make things worse by bridging DPC's. Removing a small section might indicate the state of the bricks behind the plinth?

10. there's probably enough ventilation between the joists.

11. pics of the c/breasts please. Blocked flues (all flues) should be swept and smoke tested.
There should be a vent in the blocked flue and an air terminal in its chimney pot.

14. What am i seeing in pic 1. - after remedial work or before?
After.
In pic 2. what was the dark cobwebby wispy material on the left?
I think you mean the old paint that was under the skirting.

There are suspicious signs of "something" in the cavity pics - could you hook out and pic some of the green sparkling material, and some of the white stuff (does the white stuff have strands?
Green stuff is the rock wool insulation that was blown in. The white stuff is not there any more, it was hoovered out, I think it was just cobwebs?

The black grainy debris in your cavities is most likely mortar droppings from when the walls were carelessly built.

So smells and feels like soil though?

Pic of the rear elev. please?
Rear evaluation inaccessible due to hallway furniture again it..

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ree said:

3c. Unless its real easy to insert perhaps leave the front step alone, if the cavity is clear things should be OK.

It should be once the door frame is removed, I will have a look, new door being fitted soon.

14. If you as DIY'er re-plastered the wall then so be it but if a professional did the work its not up to standard. Plus, we always rendered with S&C or S&L&C never using gypsum plaster (which you have on the wall).
It was me I was getting moaned at for it being down to brick for months, so i just put on what i had available at the time. May I just ask why s&c (i presume this means sand and cement) as opposed to gypsum plaster..S&C I always though was mortar, as for bricks, but is it suitable for plastering?..I imagine its a lot tougher when set? does it go on easy too?

The plaster should have been removed up to the work top(?).
It would have been if I had seen it getting worse, luckily it dry up and went away.

I suspect that the dry rot entered the kitchen thro the cavity.
Through the rear lounge cavity? A question for you Ree, Can dry rot manifest itself in block paving and then transfer to the house brick..There was one pallet of block paving that we suspected, it was very wet and full of white stuff, I presumed this was just effervescence? this pallet of paving took a long time to dry out compared to the others.

Just keep a future eye on all "remedial" areas, & the opposite side of that wall.
will do.

The "white stuff" was not cobwebs - however if you encounter it again then pic and post please.
I will do you think it was dry rot strings? I thought it was cobwebs covered in dust from the upper cavity, and the fact a huge spider came running out of there



The rear elevation i'm referring to is an outside pic of the rear elevation outer skin.
I know but half the hallway is against it, so nothing to be seen here at present.

Slightly over the top but if you were to use a (rented) Thermal Imager on the outside of the house it would locate any gaps in the cavity fill and possibly any damp and cold spots.
Not over the top at all, as I have also thought about this, just there expensive to buy and not sure where to hire one from...I have been round with a digital lazer guided thermometer though.

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Sorry been engaged in the plumber forums....

ree said:

Its a good question: answer, because we always did it. But i think the S&C withstood the chemical treatment to the background wall and any residual damp. Best practice was to use S&C or S&C&L as a render in all remedial areas. Belt and braces.

Of course S&C is suitable for "plastering", look at any exterior render.

Best practice with dry rot is to remove the plaster 1m (if possible) beyond signs of the infection.

No, the block paving issue is irrelevant. The cavity in question was the rear elevation cavity. Your difficulties appeared to start with a lack of thro ventilation.

FWIW: in the spider's webs, and on the wall - what was that white stuff?
I don`t know, it might have been thoses crystals again, or is it effervescence? I will see if I can find anymore.

So you are storing hall furniture in the back yard/garden against the rear elev wall?

Yes we have a roofed porch type thing on the back evevation.

FWIW: Call HSS hire for instance or google for imager rentals.

Still no pic of the c/breast?
not mine but similar, the blocked off one has a 3 piece suite against it, but similar to the 1st.

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