Flooded Home Timber Frame Repair.
Flooded home damage
One of the most heartbreaking things that can happen to a homeowner, is to be the victim of a flooding event. To see your home knee deep or worse in floodwater, is a horrible thing to endure. But people are resilient, so when the floodwaters subside, the cleanup and repairs begin.
Timber Frame Repair
One of the biggest concerns in repairing flood damage to a home is the timber frame itself. Most councils or insurers, will require the plaster and insulation to be removed and the frame inspected for structural damage before giving the green light to reclad the walls. Given that the frame is thoroughly wet, it needs to dry out. There are two major issues that will occur if the frame is still wet and not properly dried:
- Mould. As all mould species needs moisture, damp walls including masonry, plaster and timber frames, are prone to attack. Mould can cause serious health issues, as they have spores which become airborne and when breathed in, can result in serious respiratory disease or allergic reactions.
- Wood Rot. Closely related to mould, wood rot needs moisture to grow. If a frame remains damp, wood rot can develop very quickly, especially in hot, humid conditions. Wood rot will significantly weaken a timber frame, including making the house structurally unsafe. Most timber frames in Australia are radiata pine, which is susceptible to the quick onset of rot, even when treated to H2 (H2 treated timber is to protect against borer and termites only. H2 will not control wood rot, as stipulated in AS1604).
This photo shows what can happen when a timber frame remains damp for a while, which the owner not knowing. It was sent to Preschem by a customer, who had a suspected moisture leak and rising damp from a new concrete slab.
What you are seeing here is the combination of brown rot and white rot. Note that the white rot has spread into a fan like structure. This is mycelium searching for another spot where there’s damp timber. This is at an advanced stage of decay and the structure is called a fruiting body. This link will take you to that article.
Drying out the frame involves the use of fans and heaters over several days or even weeks. Is there something you can apply to the damp frames and even brickwork or masonry, that will kill both mould and wood rot?
Yes. No Rot Gel.
No-Rot Gel is a wood preservative that contains two active ingredients, Boron (as Disodium Octaborate Tetrahydrate) and Benzalkonium Chloride. Both actives excel at controlling rot and moulds. Boron even has the benefit of being an insecticide, so offers some protection against borer and termites. It is the perfect product to deal with remedial work on your flooded frame.
How do you apply No-Rot Gel?
No-Rot Gel is a ready to use product, so straight out of the bottle or drum. You will get approximately 4m2 per litre coverage to help you calculate the quantity needed.
Believe it or not, the best time to apply No-Rot Gel to a flooded timber frame, is when the frame is still damp. If parts of the frame have started to dry, then wet the frame again before application. This will help draw the product deeper into the timber. A normal dose requires two applications, so as soon as the first “coat” is absorbed, apply the second one, or start the second one no later than 2 hours after the first. Note that it will take up 3-4 days to be touch dry afterwards. This is normal.
You can apply No-Rot Gel with a paint brush, roller or spray gun, and these will wash out with water to clean up.
Is it safe for a family home?
It is safe for use in your home. Once dry there is no odour. It is a registered product with the APVMA, and they have independently evaluated the product and considered it to be safe for general/DIY use. While No-Rot Gel is a chemical, you must read the label and follow the safe handling instructions. If you’re going to spray it on, please wear an organic vapour rated mask so you don’t breathe in the mist.
Where can I buy No-Rot Gel?
Mitre 10 sell the 10 litre and 20 litre drums of No-Rot Gel via their Click and Collect system. The Timber Care website is another retailer who caries stock of all No-Rot Gel sizes, and will ship Australia wide. In both cases, the product will be despatched within 24 hours.
Your notes on how to use No-Rot Gel say ‘ that it will take up 3-4 days to be touch dry afterwards. This is normal.’
Q 1. But what happens if it rains again? Will the chemicals be dilute and lose efficacy?
This raises the issue of sealing the ends
I have a recently replaced some Spotted Gum decking boards for a client – many of those boards that I left are ok at present but showing signs of weathering on the end
I will treat with all No-Rot Gel but wanted to offer more protection to protect the boards from further egress at the ends after treating them.
I have seen several wax based emulsions that apparently give several years of protection.
Q 2. Does Preschem have such a product?
Q 3. If not, what does Prechem recommend that is compatible with NoRot Gel?
G’day Hugh,
Q1. One flooding event after treatment will diffuse some of the actives out of the timber but not all. Unless of course the standing water is there for several days or weeks. At that point you’re back to square one in a flood event. But it should help prevent mould once the water subsides.
Q2. You’ve mentioned that recently replaced spotted gum decking boards are showing signs of weathering on the ends. If you’re refering to the grey weathering then that’s a UV reaction. A Decking Oil product like Aussie Clear range will minimise this and also protect it against dimensional stability issues as it seasons insitu, by controlling the rate of moisture uptake or drying. So it’s less likely to cup, split, warp etc.
Q3. Firstly, with Spoted Gum, its a class 1 durability timber, which means it has a probable life expectancy of >40y above ground, as defined by AS 5604. It doesn’t really need a preservaitve system.
With a weather exposed deck, we wouldn’t recommend No-Rot Gel as a preservative, because the rain will eventually wash it away. If you were really wating a preservative, then Clear Wood Preservative would be the recommended option, as it dries clear and is compatible with oil based decking finishes like Aussie Clear.
I hope this makes sense.
Rohan