Mycelium in floor cavity....

[Dave Liquorice]

The ones used by the trade may be but

available to the GP AFAIK, contains propiconazole and flurox, what ever they are other than a fungicide and insecticide...

[Brian G]

[Andrew Gabriel]

This is what happens when the cellulose is removed from timber, ands that's the component all rots attack timber for, leaving the timber in much the same state. Dry rot which had eaten that much of the timber would typically have visible hyphae coming out of the timber in search of more timber (cellulose) to eat.

Without a picture, I can't say. Could be a dry rot fruiting body, in which case the infestation is more extensive than your original pictures suggest. Could be dirty cob webs.

[Peter Parry]

Its possible that originally water was largely kept out by using a French Drain around the house. Over time people may have forgotten how important it was and filled it in or covered it.

[Appin]

The message from Peter Parry contains these words:

I think that's extremely likely.

Traditional practice before the days of dpcs was to drain the site. Thus there was no real need for a dpc. In all too many places the old site drains and field drains have been broken, leading to a rise in the water table.

Hence my advice to

1. Ensure the water table never rises as high as the soil in the crawl space.

1. Get rid of any damp earth out of the crawl space and, because 1 above may be impossible to achieve fully, cover the ground in the crawl space, as far as possible, with weighted polythene

2. Cut out and replace the affected timber.

1. Because 1 and 2 may not have been fully possible and because there may be some timber left that there was a question mark over, soak all the timber in rot preventer. No, they didn't use it 200 years ago, but they were likely to have had better timber available!

It's always better to have more than one line of defence!

[mail]

On 1 Jan, 15:11, " [e-mail]" wrote:

Mark To answer your question - Yes I have well in excess of 30 years experience of this sort of problem involviing several thousand properties. The original joists are affected almost certianly by C puteana (a wet rot) and the reasons for my belief are supported by the absence of mycelium, a thin veneer of sound timber and characteristic waving of the surfcace. {Cuboidal cracking is typical of Brown rot and both dry rot and C puteana are brown rots and have an identical decay mecanism biochemically. See BRE digest 299 front photos. The photographs as so small as to make it very difficult to identify the fungus - which is difficult enough to do by good photographs in the first place. However I I am able to incline toward an indentification which is either Asterostoma or Fibroporia vaillaintii proabably the latter on the new wood on the oversite. I would GUESS my degree of accuracy on this diagnosis to be at about the 70th percentile and would not go much above this until you provide better definition photographs. I would estimate the probablity of this being dry rot Serpula lacrymans at less than 10% on the basis of mycelial distribution and the apparent lack of a definate water source - a positive requirement for true dry rot The advice - which I have skimmed given by others on the forum - is in the main both wrong and well out of date. Let us suppose it is dry rot. The recommended action is outlined in BRE Digest 299 and consists of primary and secondary actions. The primary actions are to

1) cut out the active water source I have yet to see an attack of dry rot without a leaking pipe or similar postitive source (as opposed say to condensation or rising damp) 2) promote drying conditions

ALL OTHER ACTIONS ARE INCIDENTAL and not always/often needed at all but can conisist of (not in this order...)

1) Cutting out infected timber (it is not necessary to cut 1 mm let alone 1 m beyond despite the publications to the alternative which have no basis in scientific or empirical fact) 2) replace with pressure treated timber 3) isolate existing and replacement timbers with a dpm 4) Promote drying conditions by increasing and/or establishing ventialtion 5) ONLY if it is active and infected in the masronry apply a masonry biocide 6) Removal of plaster ONLY such as to enable establisment of the full extent of the outbreak (exposure works) 7) replastering with cementatious or non-gypsum based products 8) altering the design if needed to promote better conditions for the timber

What is required here (subject to getting better photos and a plan) is probably

1) remove the debris from the oversite 2) hit all orignal timbers with a large lump hammer and discard all those that are unsound (most?) 3) replace in C(C)A - treated [tanalith] treated timber with preserved end grain abutting wall end and cut end in centre of room 3) dip treat any cut ends 4) isolate all wiht dpc 5) put in THRIOUGH sub floor vents at 3500mm sq per 1.5 m run of external wall ( say a 9" x 3" every 1.5 to 2 m perimeter) Dont spray with chemicals - dip treat for min 60 mins Do get diagnosis confirmed by CSRT qualilfied surveyor

Best wishes chris

[Brian G]

> Dear Mark

Agreed - I am not convinced on the basis of those photos either.

That is your opinion, but as this is really a d-i-y group and as such, many of the poster may lack the experience to form a definite opinion or suggest a either the scientific or practical treatment.

Not entirely true - if there are no leaking pipes but confirmed evidence of rising damp - then draw your own conclusions.

Yes, I have seen and dealt with that.

Disagree on the empirical fact as in the years that I have dealt with housing maintenace (some 40) I have seen dry rot spoors quite a distance away from the main infection site in timber necessitating complete replacement.

replace with pressure treated timber

Agreed

NLY if it is active and infected in the masronry apply a masonry

Disagree - you are obviously well aware that "true" dry rot can traverse through brickwork, so it must surely make sense to chemically treat suspect areas even if spoors are not *obviously* evident - prevention is far better than cure - and far cheaper at this stage?

Disgree for the reasons above.

Agreed - but I would rather see the site than diagnose from photograps - no matter how good they are.

A little unscientific in your case - but discard all lengths of infected timbers - do not attempt to splice pieces in or leave sound timbers in place that have been in close proximity of "true" dry rot.

Agreed

Agreed

A bit difficult to treat timbers cut along their length by dipping - so spray or dip is subject to the local conditions.

Agreed and one who is a member of the BWPDA - preferably before repairs begin.

Brian G

[mgreen02]

There are dry rot spores everywhere, its whether or not they can germinate that matters. For that they need timber with a moisture content of 28%+ If you ensure theres nowhere for the spores to germinate you have no problem with dry rot. Replacing timber just because it has spores on it is madness.

Coniophora, cellar rot, can traverse through brickwork. People seem to make less of a fuss about that. Why treat timber that will not become decayed? The fungus' own biology (and the biology of any fungus) prevents in attacking dry timber- why waste fungicide other than appease your paranoia? And cheaper? The fungus has hardly done anything, removing the props clearing the rubbish and drying the void would have to happen anyway.

There's clearly no need to remove plaster in this case. And why any should be replaced only in cement if the wall was dry escapes me.

The difference between those two statements is massive. The first suggests using someone who has a basic knowledge, the second suggests using someone who may well be a salesman. I would suggest 'uncommissioned' CSRT surveyor.

[mail]

Dear Brian G I have this vague feeling we have crossed swords before but may be wrong. In order to make it easier to see my comments on your comments on mine I am going up to UPPER CASE and not "shouting" so forgive me, please. Where we agree I have deleted the text.

I AGREE SO, AS SOMEONE WHO IS QUALIFIED (AND PROBABLY THE BEST QUALIFIED PERSON NATIONALLY OR INTERNATIONALLY IN THE FIELD OF DRY ROT IN BRITISH HOUSES) I AM SPENDING TIME IN PROVIDING AN ALTERNATIVE VIEW TO THOSE THAT CONTINUE TO PROPAGATE THE MYTHS AS EXEMPLIFED BY THE MAJORITY OF THE POSTINGS ON THIS ITEM STARTING OFF WITH THE DIAGNOSIS OF DRY ROT SO MANY (BUT NOT ALL) LEAPT TO WITHOUT ANY SUPPORTIVE EVIDENCE.

ENTIRELY TRUE IN THE OPIONION OF THE 3 AUTHORS OF BRE DIGEST 299 WHO BETWEEN THEM AT THE TIME OF WRITING IN CIRCA 1970S HAD 130 YEARS OF EXPERIENCE AND WHICH IN MY OPINION HAS ONLY ONE RELATIVELY MINOR MISTAKE (TIMBER REMOVAL) WHICH ON INVESTIGATION OF THE MAIN AUTHOR (DR J SAVORY) UNDER WHOM i WORKED AT BRE ON AN INTERNSHIP IN EARLY 1970 SAID THAT HE PUT IT IN AS A FACTOR OF SAFETY NOT ON THE BASIS OF SCIENCE.

- if there are no leaking pipes but confirmed evidence of

IN SEVERAL THOUSAND SURVEYS I HAVE YET TO SEE AN ATTACK OF DRY ROT CAUSED BY RISING DAMP. YOU ARE, OF COURSE, ENTITLED TO YOUR OPINION BUT MANY BEFORE YOU HAVE ALLEGED TO ME THAT THE DRY ROT WAS CAUSED BY RISING DAMP AND ON INVESTIGATION IS WAS EITHER WET ROT - Fibroporia vaillantii (false dry rot) C puteana or if actually DRY ROT THE CAUSE WAS FOUND TO BE A LEAKING DOWN PIPE OR THE LIKE AND THE RISING DAMP WAS INCIDENTAL. THERE IS A HIGH INCIDENCE OF RD CAUSING WET ROT. I HAVE YET TO SEE ANY VALIDATED CLAIM THAT RD on its own CAUSES DRY ROT. REMEMBER THIS IS THE RESULT OF SEVERAL THOUSAND SURVEYS AND COLLABORATION WITH OTHER COLLEAGUES. HOW MANY HOUSES ARE YOU TALKING ABOUT AND WHICH QUALIFIED MYCOLOGIST OR CSRT SURVEYOR DIAGNOSED THE DRY ROT?

IT IS NOT POSSIBLE TO SEE AN INDIVIDUAL SPORE. [SPOORS ARE ANIMAL TRACKS] ALL YOU CAN SEE IS A LARGE COLLECTION OF SPORES IN THE FORM OF A RED POWDER LIKE CAYENNE PEPPER EVEN IF YOU COULD SEE A SPORE OR ARE REFERRING TO SPORES THEN SO WHAT?

quite a distance

THERE IS ABSOLUTELY NO NEED TO REPLACE TIMBER BECAUSE IT IS COVERED IN SPORES. I WONT BOTHER TO ARGUE THE EVIDENCE AS IT IS MOST PROBABLE (ALBEIT A GUESS) THAT YOU ARE ACTUALLY REFERRING TO MYCELIUM AND HAVE NOT THE QUALIFICATION TO KNOW THE DIFFERENCE iF IT IS MYCELIUM TO WHICH YOU REFER THEN YOU ARE USING THE INCORRECT TERM AND EVEN THE PRESENCE OF MYCELIUM DOES NOT OF ITSELF REQUIRE COMPLETE REPLACEMENT. THE REASON FOR THIS IS QUITE SIMPLE. THE PRESENCE OF A HYPHAL STRAND ON OR EVEN IN A PIECE OF TIMBER DOES NOT NECESSITATE ITS REMOVAL. ONLY IF DECAY HAS CAUSED THAT TIMBER STRUCTURE TO FAIL IS IT NECESSARY TO REPLACE THE STRUCTURAL EFFECT OF THE TIMBER. I HAVE SAVED MANY AN HISTORIC CEILING OR PANELLING IN GRADE 1 LISTED PROPERTIES BY JUDICIOUS SCRAPING OFF OF SURFACE MYCELIUM OR EVEN MINOR DECAYED TIMBER AND CONTROLLING THE DRY ROT BY OTHER MEANS SAVING PRICELESS HISTORIC FABRIC. I HAVE DONE THIS BOTH AS CONTRACTOR AND CONSULTANT AND NOT HAD ONE GUARANTEE CLAIM OVER A 30 YEAR PERIOD. YOU HAVE BEENN BEGUILDED INTO FOLLOWING "THE RULES FOR THE MANY" ESTABLISHED BY THOSE WITH A VESTED INTEREST [TIMBER TREATMENT COMPANIES] AND HAVE NOT THOUGHT THIS OUT FROM FIRST PRINCIPLES YOURSELF. THEY WERE AND ARE WRONG AND YOU HAVE MISTAKENLY BELIEVED THE COOKERY THAT THEY PROPOSE

YOU DISAGREE???? SO YOU ARE ADVOCATING TREATING AN INACTIVE NON INFECTED MASONRY ON THE OFF CHANCE????? TO TREAT AN INACTIVE ATTACK AS YOU ARE NOW SUGGESTING COULD LEAD YOU (WERE YOU TO DO IT) TO BE AT THE WRONG END OF CRIMINAL PROCEEDINGS UNDER THE COSHH REGS

you are obviously well aware that "true" dry rot can traverse

NO. THE CRITERIAL FOR TREATMENT WITH A BIOCIDE ARE SELF EVIDENTLY CLEAR THE ATTACK HAS TO BE ACTIVE (THE MAJORITY TREATED BY COMMERCIAL COMPANIES ARE DEAD) THE SPREAD OF MYCELIUM THROUGH BRICKWORK NEEDS ONLY TO BE TREATED IF IT IS ACTIVE AND IF THERE ARE TIMBERS AT RISK. A COMPETENT EXPERIENCE SURVEYOR WILL LOOK AT THE STRUCTURE - ASSESS IF THERE ARE TIMBERS AT RISK - ASSESS THE DRYING OUT TIME (CRITICAL) AND ONLY ON THAT ASSESSMENT DETERMINE IF A BIOCIDE IS NEEDED. UBIQUITOUS "DRILLIING AND IRRIGATIING" IS A CON AND SHOWS A FUNDAMENTAL LACK OF UNDERSTANDING OF THE BIOLOGY OF THE FUNGUS WHICH IS VERY SUSCEPTIBLE TO REDUCTIONS IN rh AND TEMPERATURE. WHEN OPERATING COMMERCIALLY ONLY ABOUT 30% OF THE ATTACKS OF DRY ROT WE WERE CONTROLLING REQUIRED A BIOCIDE IN THE BRICK OR MASONRY

I SUSPECT WE ARE NOT TOO FAR APART BUT APPROACHING IT FROM DIFFERENT ENDS. I DO EXPOSURE WORK BUT NOT 1 M BEYOND REGARDLESS. I USE A MOISTURE METER - EXPERIENCE AND KNOWLEDGE OF THE BUILDING STRUCTURE AND KNOWLEDGE OF THE FAVOURITE ROUTES OF DRY ROT ( BACK OF WALL PLATES ETC) AND TAILOR MY EXPOSURE REQUIREMENTS TO THE CONDITIONS. IF YOU ARE ADVOCATING 1 M PLASTER REMOVAL REGARLESS - THAT IS ARCHITECTURAL VANDALISM BORN OF PROFOUNDLY IGNORANT FOLLOW MY LEADER BELIEF WHICH HAS BEEN PROVEN UNNECESSARY FOR THE LAST 20 TO 25 YEARS.

AGREED HENCE MY LIMITATIONS BUT i WOULD PUT MONEY ON MY F vaillantii diagnosis

I WAS MAKING A RECOMMENDATION FOR A LAYMAN TO DETERMINE WHERE THE TIMBER IS FIT AND WHERE NOT FIT

I HAVE 40 YEARS "ON THE TOOLS" BEING A SITE MAN AS WELL AS A SCIENTIST AND THIS IS STILL THE BEST PRACTICAL METHOD FOR A LAYMAN. PERSONALLY, I LOOK AT AND TEST THE OVERALL JOB AND CUT OUT WHERE NEEDED WITH A CUT SAW. ONLY OCCASIONALLY - SAY WITH HLH DOES ONE NEED TO USE A HAMMER AS SUGGESTED.

THERE IS NO NEED TO TREAT TIMBERS IN SITU THE DIPPING WAS FOR THE NEW TIMBERS IF YOU WERE WANTING TO TREAT CUT ENDS OF THE IN SITU TIMBERS - AND THAT IS NOT A BAD IDEA - THEN A POLY BAG OVER THE END AND DRIP FEED IT OR SEVERAL GENERAOUS BRUSH TREATMENTS WILL DO NO HARM BUT STRICLY SPEAKING IS NOT NECESSARY AS SUCH CUT ENDS ARE NOT REALLY AT RISK AS THEY HAVE STOOD THE TEST OF TIME IN THAT LOCATION IN THE PROPERTY. EQUALLY ONE COULD ARGUE THAT IT IS NOT NECESSARY TO TREAT THE NEW TIMBER BUT SINCE IT IS EASY TO DO BY DIPPING AND IN THIS LITIGIOUS WORLD A CONTRACTOR IS ILL- ADVISED NOT TO

YOU ARE WELL WELL OUT OF DATE THE BWPDA EFFECTIVELY CEASED TO EXIST 18 MONTHS AGO THE PCA SPLIT FROM THE WPA AND THERE IS NO LONGER A BWPDA

I WOULD NOT PUT MY TRUST IN ANY OLD BWPDA MEMBER - SOME OF THEM WERE RIGHT ROGUES - ONLY A FEW - AN SOME WERE COMPLETEY INCOMPETENT - USUSALLY THE OLDER SINGLE TRADER WHO HAD NOT KEPT UP WITH THE TIMES AND WAS STILL DRILLING AND IRRIGATING AND GOING A METRE BEYOND AND FAILING TO TAKE ANY EXAMS SUCH AS THE CSRT

HENCE MY SUGGESTION OF A CSRT SURVEYOR

CHRIS

[mail]

Dear mgree

Thanks for a breath of fresh air on this...

SPOT ON

THE REASON FOR THIS IS THAT SUCH SPREAD IS NOT A MECHANISM FOR REINFECTING NEW TIMBER IN THE SAME WAY AS DRY ROT DOES AND THERE IS NOT THE SAME CAPACITY FOR WATER TRANSLOCATION TO THE NEW HYPHAL FRONT. AS YOU SO RIGHTLY OBSERVE ELSEWHERE THE PRESENCE OF SPORES OR MYCELIUM IS NOT OF ITSLEF A HUGE PROBLEM REQUIRING NO MORE THAN TO PROMOTE DRYING CONDITIONS

Why treat timber that will not become

SPOT ON

The fungus' own biology (and the biology of any fungus)

SPOT ON And cheaper? The fungus has hardly done

DEAD RIGHT

CORRECT AND I WAS NOT REFERRING TO THIS CASE BUT GENERALISING ON BRE 299 FOR DRY ROT I BELIEVE THIS CASE IS NOT DRY ROT

And why any

IT IS A LITTLE KNOWN OBSERVATION THAT DRY ROT DOES NOT INHABIT AND SPREAD WELL IN CEMENT MORTAR BUILDINGS (DUE TO THE PH REQUIREMENTS) IT IS MUCH MUCH MORE PREVALENT AND VIGOUROUS IN LIME MORTAR BUILDINGS (YOU MAY HAVE BEEN REFERRING TO CEMENT "MEANING MORTAR" )

OH SO RIGHT The first

GOOD IDEA - SHOULD HAVE THOUGHT OF THAT MYSELF! IRTS?

cHRIS

[mgreen02]

No problem.

Really? All wood-decay fungi translocate water to the hyphal front and Coniophora does a great job of destroying embedded timbers. I'm half- tempted to get you state a reference, but I think I get the spirit of what your getting at. Unless you're suggesting that it moves water to the hyphal tips to wet up dry timber...then you can cite your sources. ;-)

I've not seen Antrodia produce mycelium like that it tends to be whiter and more fan-like from experience. Not that it matters overly in this case. The recommendations are more or less the same, with a bit more of a watchful eye on the solum in the void in the case of dry rot.

Well, I can't argue with that much. Fair enough, although most cement mortared buildings have cavity walls too, which prevents a lot of water from gutter and rwp defects getting to the timbers. It would be an interesting back-to-back comparison though. Whether that is cause to use cement where once was lime is an entirely different debate.

Cheers.

[Brian G]

Chris, you are correct - we have disagreed before. And yet again, I disagree with a lot of what you say and find your method of explanation in a type of 'very closely typed Technical Report' format difficult to read and extremely boring.

Before taking early retirement, I spent some forty years 'on building maintenance' as a tradesman and supervisor and have had to deal with many so-call professionals and over the years - and put things right when their solutions didn't work.

I have even had to stand up in court to defend their specifications when things have gone seriously wrong and clients/tenants have sued - so I do really know what I am talking about on a *PRACTICAL and THEORETICAL* basis - that may explain why the term surveyor etc puts me into a crusty old sceptical mode.

As a matter of interest, I did manage to read this 'report' and did respond, but after reading my reply I decided that some of the comments on your claims and knowledge would have left me open to libel proceedings as this is an open forum - so I took the easy way out and deleted the whole post - unusual for me as I tend to call a spade a spade - I must be getting old :-)

BTW, many of the people using this group wouldn't know what a 'BRE Digest' was if it hit them on the nose (yes I have read them, I left lever arch files full of the damn things for my successor [including many 'reports' from dry rot surveyors]) - along with some of the technical jargon you use.

Lets now call a halt to this before things get a little rancorous and agree to disagree.

All the best

Brian G