Antifungal Course in bathroom and DPC course , pls help

[platforminc]

Hi All,

I’m embarking on a project to install a new bathroom/toilet suite. Now the current floor can be described as rotten at the moment. Some of the joists will need to be replaced and a new flooring installed together with new tiling. The bathroom is suffering from true dry rot on (flooring, joists, bearer plates skirting board and masonry). During the inspection, it was decided by a DPC company that some parts of the bathroom will have the existing plaster hacked off, a anti fungal chemical injected, left to dry for a few weeks and then the walls re-plastered. They also said that new joists will be fitted with pre-treated wood. They also said that the wood will be isolated from the wall plate/brick pier/brickwork using a physical damp proof membrane.


The question that I have here is that, the charges for the DPC company are a bit on the high side, a mate of mine told me that the chemical DPC can bought and a machine to inject the chemical into the wall rented as well. He also suggested that a builder can do all of this.
My question is that where can one buy the chemical from and what is the name of the machine that injects the chemical into the wall and where can it be hired from?

This is for the bathroom/toilet. Secondly there is a requirement for a vertical 1.5 metre high DPC chemical course on the ground floor living room space also. I understand that the chemical takes a few weeks to dry out, is it possible to get one which doesn’t take a long time to dry out. Does anyone know what DPC course I can buy to get my builder to carry out the works.


Any info or help will be most appreciated.

There are a couple of obvious questions to ask, the first and most obvious being, is it a ground floor bathroom? If not then I don't really understand all the talk of chemical DPC's. that being said I don't understand why you would use it anyway.

Lets discuss the dry rot first. There have been many chemical treatments recommended for dry rot but you simply don't need them and even if you did, Boron isn't one of them, Boron is more often specified as a woodworm treatment and I've found no mention of this in your thread.
Best practice treatment for dry rot is to simply, eradicate the source of moisture, introduce rapid drying and increase ventilation. Keep timber moisture content below 20% and you won't have a problem with dry rot, simple as that.
In terms of the damage done to existing timbers then yes, of course these will need replacing at least one meter back from the last sign of infection. The serpula Lacrymans fungus feeds on the lignin (part of the cellulose) within the wood and this is what causes the wood to crumble and lose its strength. Obviously use pressure treated timbers and if building into the brickwork you simply wrap the joint end in a plastic boot made from a roll of DPC and a staple gun. Alternatively simply place the timbers on joist hangers.
Do not waste your time or money on chemical DPC injection, if the plaster is defective then replace with a renovating plaster such as limelite but DPC injection is not necessary.

Critical to all recommendations is an understanding as to where the bathroom is. I've assumed ground floor, obviously with timber floor and sub floor void. If you have dry rot then sub floor moisture content is high and you will continue to have problems until you deal with the problem at source rather than considering management solutions like chemical treatments etc.
Remember... Eradicate the source of moisture.! Is there a leak under the floor or is it caused purely from ground moisture? If no leaks then fine, you simply have an issue with poor sub floor ventilation. Inspect your air bricks. Have you got enough or do you need to install more? I have to say that the advice given by pinenot is complete nonsense and shows a very poor understanding of these issues. Particularly his advice to 'Hack out affected brickwork', as I said, complete tosh!

The bathroom/toilet is on the first floor and not groundfloor.
What are your thoughts on the dehumudifier, and where can I find a meter to measure this ? Any good place you can recomend to rent a industrial strength dehumidifier ?

The hacking off the plasterwork is what was written in the damp and timber report carried out on the house. I guess these are areas previously affected by damp.

 

[platforminc]

really,plz explain what parts you think are not to your liking.im not agreeing with all of his recommendations but most make perfect sense to me.

Hack out brickwork? Ridiculous idea!

Run dehumidifier until moisture content is 10%. What moisture content? 10% is high for brickwork and very low for sub floor timbers.

Skip what DPC? No mention of DPC and the idea that you can sterilise for dry rot by throwing everything into a skip is ridiculous.

Good ventilation throughout the house? Another ridiculous recommendation that might be more appropriate for condensation damp but it isn't anywhere near specific enough for treating dry rot.

I could go on but I think that's enough to be going on with.

the op mentions a chemical dpc in his original post.
maybe he meant the plaster/render to be skipped?
as for the wall treatment there is either diamond drilling or containment,
ventilation,maybe all those air bricks ive put in over the years were a waste of time then?
as for wrapping the joists ends i understand that perfectly as thats what i do.
i too could go on,
1 thing the op hasnt mentioned is whether the walls are cavity or solid.

You're disagreeing with one of my points on the basis that maybe the OP meant something else. Maybe he meant skip the render or plaster... Genius, don't know about you but I always like to keep the old plaster and render that I hack off, it looks lovely scattered over the flower beds. Or maybe you can tell me how you dispose of a chemical DPC in the skip?
You're confusing the point about ventilation as much as pinenot did... He recommended improving the house ventilation and this is completely meaningless for the treatment of dry rot. What have air bricks you installed got to do with anything? If you installed them as room ventilation, then yes, they'd be a waste of time for treating dry rot, if you installed them to ventilate the sub floor then that would not be a waste of time for treating dry rot.
As for wrapping joist ends, nothing wrong with that and I didn't disagree on the point suffice to say that Visqueen isn't really durable enough for this application and I would recommend a roll of polyethylene DPC as being a better choice of material.
How does the distinction between solid and cavity walls affect the advice given for treating dry rot?
If you can go on then I hope you have a point to make because the point was decidedly absent from your last post.

The wall is a solid brickwork.

 

[platforminc]

Just realised that the picture i intended to attach wasnt actually attached. Attaching it again, I think this is what is causing confusion.

View media item 60822

 

[gregers]

well if its 1st floor then it isnt rising damp thats caused any problems so no need to put a chemical dpc 2 meters odd up in the air lol.

 

[platforminc]

well if its 1st floor then it isnt rising damp thats caused any problems so no need to put a chemical dpc 2 meters odd up in the air lol.

The DPC is for the ground floor, please see picture at the top.

 

[^woody^]

With this and pinenot ...... pass me the nurofen

 

[pinenot]

Faced with all the hot air you spout, I found it too hot, standing too close...pinenot

__________________________________

”Had it not been for you, I should have remained what I was when we first met, a prejudiced, narrow-minded being, with contracted sympathies and false knowledge, wasting my life on obsolete trifles, and utterly insensible to the privilege of living in this wondrous age of change and progress“. Benjamin Disraeli

 

[Joe Malone]

have you actually got your hands dirty doing this kind of work?or are you a suit?not have a pop m8 just inquiring
if the wall is a cavity then its going to be a bit difficult in drilling it out for dry rot treatment but then i wouldve thought you would know that?,also it may well be blocked so installing a chemical dpc will be a waste of time without clearing out all/any crud that may be there,also only inside skin needs to be injected.
the op has gone quite on this thread along with pinenot ?

I'm your worst nightmare, a suit who also gets his hands dirty! Where on earth did you learn to treat dry rot because not having a pop m8 but you don't know what you're talking about. You're obviously in the business of charging customers for high priced chemicals that they don't need. Treating masonry for dry rot is a pointless exercise and even more pointless when you start injecting into cavities? Why would you do that? Chemical treatment for dry rot is nothing more than a management solution, it isn't a cure. Again, best practice to achieve a cure for dry rot is, eliminate the source of moisture, introduce rapid drying and then increase ventilation. No chemicals needed just small building works for the replacement of affected timber and installation of air bricks etc. Wear your 'I get my hands dirty' badge with pride m8 but at least learn the theory to make sure it was worth getting your hands dirty for.

 

[Joe Malone]

well if its 1st floor then it isnt rising damp thats caused any problems so no need to put a chemical dpc 2 meters odd up in the air lol.

The penny drops.

 

[platforminc]

Joe

Based on the info on the diagram, what do you suggest here?

Thanks in advance

 

[Joe Malone]

Joe

Based on the info on the diagram, what do you suggest here?

Thanks in advance

First consider why you have got dry rot in the bathroom and the most logical answer to this is long term undetected plumbing leaks. I would even question whether it is dry rot given the location, are you sure it's not wet rot? Have you seen any signs whatsoever that dry rot is active? Wet and dry rot both cause cuboidal type cracking in timber and to the inexperienced it is very difficult to distinguish the difference. With dry rot you might also see a white cotton wool like growth (mycelium) or rust coloured dust (spores) that has been ejected from a sporophore which is a mushroom like growth. The white strands coming from the mycelium is called hyphae or feeder strands. These are what provide the main body of growth with food in the form of glucose. People talk about sterilising or treating brickwork because the hyphae has the ability to spread across inert materials like brick. However it will cause no damage to the brickwork whatsoever and you cannot 'sterilise' an affected area which has suffered an outbreak. Companies over complicate the treatment because there's money is selling expensive chemicals that aren't needed. Make sure you have no plumbing leaks, check all pipe work and wastes with taps running. You must have a source of moisture to have caused either wet or dry rot. Eliminate the source of moisture. Replace any affected timbers following the guidance I gave earlier. I've no idea whether the brickwork in the bathroom is damp and if it is it can take 6 months to dry out so you'll struggle to get floor timbers to an acceptable moisture content while brickwork is also drying out. Pragmatically, it might be worth installing an air brick to coincide with the floor void at first floor level in the bathroom. It is worth running a dehumidifier to help dry out the bathroom but you don't really need an industrial one given the size of the space. I bought an excellent second hand unit off eBay for £60 and have been using it for two years now with excellent results. Plasterwork should be replaced if it is defective and by this I mean overly porous. Plasterwork subject to chronic damp tends to degrade as the damp dissolves the calcium sulphate contained within the plaster. Result is that plasterwork becomes very soft and porous. When I'm testing with a damp meter the pins sink easily into defective plaster but where it's sound then then a lot more force is needed to sink the pins into the plasterwork to get a damp reading. Again, pragmatically, if you are replacing plasterwork then use a renovating plaster such as limelite, this isn't specialist work and any plasterer could do this for you at very reasonable rates. Damp companies like renovating plasters because it hides the fact that the DPC treatment wasn't really needed but if you have got a damp wall then renovating plaster will dam in the damp.
I won't comment further on the ground floor until you have posted photographs of the inside and outside of the area allegedly affected by rising damp. It should tell you something that advice was being offered even before those offering that advice thought to ask whether it was a first or ground floor bathroom. A rather important distinction when chemical DPC's are being discussed. Just about any damp problem you encounter can be cured using nothing more than small building works and chemicals or specialist treatments are very very rarely required.

 

[gregers]

have you actually got your hands dirty doing this kind of work?or are you a suit?not have a pop m8 just inquiring
if the wall is a cavity then its going to be a bit difficult in drilling it out for dry rot treatment but then i wouldve thought you would know that?,also it may well be blocked so installing a chemical dpc will be a waste of time without clearing out all/any crud that may be there,also only inside skin needs to be injected.
the op has gone quite on this thread along with pinenot ?

I'm your worst nightmare, a suit who also gets his hands dirty! Where on earth did you learn to treat dry rot because not having a pop m8 but you don't know what you're talking about. You're obviously in the business of charging customers for high priced chemicals that they don't need. Treating masonry for dry rot is a pointless exercise and even more pointless when you start injecting into cavities? Why would you do that? Chemical treatment for dry rot is nothing more than a management solution, it isn't a cure. Again, best practice to achieve a cure for dry rot is, eliminate the source of moisture, introduce rapid drying and then increase ventilation. No chemicals needed just small building works for the replacement of affected timber and installation of air bricks etc. Wear your 'I get my hands dirty' badge with pride m8 but at least learn the theory to make sure it was worth getting your hands dirty for.

believe me your not my worst nightmare but close ,think you mis-understood me joe when i mentioned cavities that was more for the dpc query,the only thing if it is a cavity(dry rot) is to surface spray,but if a really bad out break where it has infected the cavity then major problems occur.i used to be in the business joe and have worked for a few large firms and some smaller 1s.

to the op,i really suggest you google 'merulius lacrymans' or 'serpula lacrymans' and read up on the info thats out there,differing opinions can be healthy but we are not putting our hands into our pockets for your problems,well joe might want to?
i certainly wouldnt be happy after having to rip out and replace whatever needs doing and not carrying out any form of eradication using chemicals that have been tested and developed over the years for this sort of work whether others have an opinion that just cutting out and introducing some air is really going to work,for it to reinfest and you having to redo it yet again at more expense to your self.

 

[Joe Malone]

have you actually got your hands dirty doing this kind of work?or are you a suit?not have a pop m8 just inquiring
if the wall is a cavity then its going to be a bit difficult in drilling it out for dry rot treatment but then i wouldve thought you would know that?,also it may well be blocked so installing a chemical dpc will be a waste of time without clearing out all/any crud that may be there,also only inside skin needs to be injected.
the op has gone quite on this thread along with pinenot ?

I'm your worst nightmare, a suit who also gets his hands dirty! Where on earth did you learn to treat dry rot because not having a pop m8 but you don't know what you're talking about. You're obviously in the business of charging customers for high priced chemicals that they don't need. Treating masonry for dry rot is a pointless exercise and even more pointless when you start injecting into cavities? Why would you do that? Chemical treatment for dry rot is nothing more than a management solution, it isn't a cure. Again, best practice to achieve a cure for dry rot is, eliminate the source of moisture, introduce rapid drying and then increase ventilation. No chemicals needed just small building works for the replacement of affected timber and installation of air bricks etc. Wear your 'I get my hands dirty' badge with pride m8 but at least learn the theory to make sure it was worth getting your hands dirty for.

believe me your not my worst nightmare but close ,think you mis-understood me joe when i mentioned cavities that was more for the dpc query,the only thing if it is a cavity(dry rot) is to surface spray,but if a really bad out break where it has infected the cavity then major problems occur.i used to be in the business joe and have worked for a few large firms and some smaller 1s.

to the op,i really suggest you google 'merulius lacrymans' or 'serpula lacrymans' and read up on the info thats out there,differing opinions can be healthy but we are not putting our hands into our pockets for your problems,well joe might want to?
i certainly wouldnt be happy after having to rip out and replace whatever needs doing and not carrying out any form of eradication using chemicals that have been tested and developed over the years for this sort of work whether others have an opinion that just cutting out and introducing some air is really going to work,for it to reinfest and you having to redo it yet again at more expense to your self.

Yes there are generally two different opinions, those associated with companies selling high priced treatments and the facts. No need to over complicate the situation because whether it's Merulius or Serpula, neither can exist in the absence of required moisture levels. Get timber moisture content below 20%, keep it there and it's game over for the fungus. The fungus will simply lie dormant and do no further damage. I'm unsure what having your own business has to do with the facts but you cannot eradicate dry rot or any form of rot for that matter. It's a convenient lie touted by those selling chemical treatments. Fungal spores are in the air we breathe so it only takes one fungal spore to settle in optimum conditions to get a fresh outbreak. It's almost comical that you would try and convince the general public that eradication is possible when those same fungal spores are present in the air we breathe and therefore ubiquitous.

 

[tony1851]

Joe's posts on dry rot hit the nail on the head. For those who don't like much reading, if he will permit me, here is a precis of them;

The most effective permanent killer of dry rot is a dry, well-ventilated environment. End of story.

 

[Joe Malone]

Joe's posts on dry rot hit the nail on the head. For those who don't like much reading, if he will permit me, here is a precis of them;

The most effective permanent killer of dry rot is a dry, well-ventilated environment. End of story.

You could argue the toss as to whether it is lying dormant or how long it takes to actually die off but it's an academic point; the précis with regard to the most effective approach is both is simple and accurate.