Rotten wood can be an invisible enemy when it comes to the structural integrity of your garden deck. Repeated moisture exposure may be lurking beneath your beautiful boards, causing dangerous deterioration.
At Trex Protect, we fight the rot problem before it starts by covering your joists, bearers, rim joists, and ledger board with waterproof butyl tape. We also recommend regular inspections of your wood to avoid wood rot and to take proactive measures.
How to Identify and Treat Wood Rot
This article covers why it’s essential to be aware of the dangers of rot, how to identify it and what to do if you find it. Unfortunately, rot is often not discovered until larger issues emerge. Thus, remain vigilant and on the lookout around the deck and around the home for rot.
Types of Wood Rot
There are two primary types of wood rot: wet rot and dry rot. While both can be damaging, they’re actually quite different. We’ll explore more below, but you might be interested to know that:
- Wet rot is less destructive than dry rot
- Wet rot will stop growing if you can remove the source of moisture.
- Coniophora puteana or wet rot is a cellar fungus
- Serpula lacrymans is the scientific name for dry rot
- Dry rot does not need a source of water ingress because it generates moisture through its digestion of timber
- Address both wet and dry rot as soon as it’s found. Dry rot will likely require a professional.
What is Wet Rot?
Simply put, wet rot occurs when high moisture leads to the natural decay of wood. Water feeds and attracts this rot fungus that affects damp timber (decks, around windows, etc.), plaster, wallpaper, and carpets. The fungi break down the wood’s cell walls and feed on its nutrients.
If dampness raises a timber’s moisture content above 20 percent, wet rot spores will germinate and grow. If a programme of timber treatment is not implemented, wet rot can cause structural failure, especially if it infects structural timbers.
When looking for wet rot, what should you check for?
- A damp, musty smell
- Timber that is cracking and beginning to soften
- A board that moves (or bounces) when you walk over it
- Discoloured or weak timber
- Visible localised fungus growth
Some common causes of wet rot include roofing defects, plumbing leaks, leaky gutters, leaks around showers or baths, condensation, and/or rising damp penetrating a wall or timber post. It can be more challenging to spot the rot if with painted wood. If you press a screwdriver into the wood, and it goes in easily, you probably have an issue.
What is Dry Rot?
Dry rot, the most severe form of fungal decay, attacks the wood in buildings. Also known as brown rot, dry rot is so named because often the wood appears to be dry, as the fungi target cellulose in the wood’s structure.
What should you look for in these wood-destroying fungi?
- Splitting and cracking of timber into small cubes
- Darker wood
- Dry or crumbly timber
- Fine, fluffy white mycelium
- Grey-whitish “skin.”
- Soft, fleshy mushroom-like body that looks like a pancake
- Red dust from spreading spores
Checking out photos online can be helpful in identification.
Causes of Wood Rot
Dry rot draws strength and moisture from digesting the wood. It requires no other source of moisture once it begins growing. However, for moisture to be in the timber, there is usually a leaking gutter, broken or leaking pipes, an issue with an appliance such as a washing machine, penetrating damp or poor ventilation.
If you find wet rot (Coniophora puteana) or dry rot (Serpula lacrymans ) on your property, seek a professional. You might be able to DIY some needed repairs, but eliminating the rot will require some experience. For starters, they will be able to determine if you’re dealing with wet rot, dry rot, or insects like woodworm, which will direct your wood treatment options — insecticide, fungicide, wood removal, etc. Because rot often grows in hidden places, you want to be sure to eradicate it.
Wet Wood Rot Treatment
The cost of any repair or remediation depends on how severely the wood is affected. If rot is widespread, you will need to replace affected timbers. The main concern for wet rot is to eliminate the source of the rot: any moisture leakage. Water damage can be your greatest cost, especially if you need to replace a roof or damage caused by a leaking pipe.
Dry Wood Rot Treatment
As with wet rot, the first course of treatment is to eliminate any source of moisture. Next, a professional will assess the severity of the outbreak. Often, this requires removing flooring, walls, or decking boards. It is recommended that any infected timbers be cut back to at least 500 mm beyond the last signs of fungal growth or hyphae strands (the branching filaments that make up the mycelium of the fungus). Also, remove any fruiting body and visible spores. Additionally, clean all areas and sterilise masonry.
Replace affected wood with pre-treated timber. Treat remaining wood with a dry rot treatment fluid; these special fungicides help stop re-infestations. A wood preservative such as Ronseal might also be useful in protecting against future rot. If the damage is not significant, a wood filler and wet rot wood hardener may help fortify timbers, especially around doors and windows.
The Cost to Treat Wood Rot
The costs for dry rot treatment are twofold. First, you’ll need to have an assessment with a professional to uncover any signs of damage. A rot survey can cost £200 to £400. Repairing the rot will, of course, depend on the damage.
If you discover dry rot or wet rot — or its signs — do not leave the affected area untreated. Property care and proactive mitigation will make a difference. The more quickly you take action, the better. The longer you wait, the more serious and expensive the problem will become!