Dry rot
The life-cycle of dry rot can be broken down into four main stages. Dry rot begins as a microscopic spore which, in high enough concentrations, can resemble a fine orange dust. If the spores are subjected to sufficient moisture they will begin to grow fine white strands known as hyphae. As the hyphae germinate they will eventually form a large mass known as mycelium, and he final stage is a fruiting body which pumps new spores out into the surrounding air.
The below picture shows the dry rot spores that are coming from the suspended timber floor where there is a dry rot outbreak
The below picture shows a very large strand from a dry rot out break
Dry rot (Serpula Lacrymans) is the most famous of the rots, and is also the most serious. If left to grow dry rot can cause thousands of pounds worth of damage, dry rot can cause timber decay at a lower moisture content than wet rot, that is why the cause of the problem needs to be identified, and rapid drying of the area is needed.
Unfortunately dry rot can also be rather ‘secretive’ in its activity, preferring stagnant, humid conditions. Hence, when it is discovered the damage it has caused is frequently very extensive.
Dry rot repair works are mostly over specified, and there is this mis conception that everything needs to be cut back 1 meter. This maybe acceptable on a 3″ x 2″ piece of softwood, but not an historic listed building. We have worked on some very large listed buildings with huge oak timbers built into soaking wet walls that would take years to dry down. Using specialist drying equipment we can tent off the areas and even pressure inject warm dry to create evaporation to bring the wall back to equilibrium. Gone are the days of leaving timbers built into soaking wet walls and taking a chance, times have changed and we have implemented this along with data logging moisture and damp readings. This gives our client complete peace of mind.
It also important that if timbers are to be left, that bearing ends of timbers are drill resistance tested to check the structural integrity of the timber. We offer resistance drilling ourselves, and is normally part of the survey full opening up is being carried out.
Dry rot treatment, and dry rot surveys need to be carried out by an experienced professional surveyor with an understanding of buildings, and the ability to kill off the dry rot outbreak first time.
We offer the complete service from initial survey, rapid drying of the area in question with specialist dehumidifiers, sympathetic repairs along with chemical treatments where necessary.
It is well documented that to kill off dry rot it is imperative that the moisture source is completely removed. We know that walls typically dry down naturally at around 1 inch per month, so it can take a number of months, for even years for a wall to dry down if left to dry naturally, potentially leaving timbers still at risk.
Top tip
When comparing quotes from contractors offering a dry rot treatment make sure that the quotation covers the cost of drying down of the areas in question with desiccant dehumidifiers, as I find very often the cheap fix quotes don’t cover this, and are reliant of chemicals only, and this is when dry rot makes it’s way back.
Common questions that we get asked.
How do you treat dry rot?
How do you repair dry rot?
Is there a diy repair for dry rot?
All the above questions really need to be answered after a survey has been carried out to ensure the correct diagnosis and repair is specified.
Wet rot
Wet rot is timber that is decaying naturally in the presence of high moisture levels.
The most common being ‘Cellar Fungus’ (Coniophora Puteana).
Any non treated timber exposed to high moisture levels can provide the ideal breeding ground for wet rot spores to germinate.
Typical causes are leaking pipes, rising damp, gutter leaks, damaged roof, and poor property maintenance.
