Will Bleach Prevent Wood Rot?

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We use wood extensively for construction and other purposes, but water is something that it should never come into contact with, at least extensively, unless it’s a boat. If wood gets exposed to water through leakage it might develop rot.

Wood rot can result in many structural problems, both indoors and outdoors especially when it comes into contact with soil. You cannot reuse rotted wood – you have to replace it, resulting in a lot of expense. Although there are no foolproof ways of treating rot, some chemicals will prevent rot from occurring. In this post, we take a look at some of the substances you can use to prevent wood rot from developing.

Types of Wood Rot

Before we go into the details of how to treat wood rot, let’s take a quick look at the common types that occur:

Brown Rot

Although we call this “brown,” the color may vary slightly. Wood affected with brown rot will crumble and breaks apart easily. If allowed to progress, brown rot will render the wood into powder, and it won’t be able to withstand weight anymore.

White Rot

White rot may not start as white – it tends to develop white color after the rot progresses further. It makes the wood soft and it has a sponge-like appearance.

Dry Rot

This type of rot is not a different kind of rot. It is the result of brown and white rot. Dry marks the total decay of the wood, when no further deterioration occurs.

Substances That Prevent Wood Rot

If you are looking for information on how to treat wood rot or prevent it, you will find a lot of information on the internet. You can easily get overwhelmed with the flood of remedies that you see. In this post, to provide more clarity on the subject, we have compiled a list of some of the most effective ways to prevent rot by adding certain chemicals. Here are a few of the most effective substances you can use:


Clorox Splash-Less Bleach, Regular, 2 Pack of 55 fl oz each/ 110 Ounces Total
Clorox Splash-Less Bleach (Image: Amazon)

There is much discussion that revolves around the use of bleach for treating wood rot. At the very outset, it is relevant to point out that bleach will not arrest or reverse the process of wood rot. You can only use bleach on impermeable surfaces, but not on porous surfaces like wood.

If you apply bleach to wood infected with wood rot, it will only attack the fungus that is present on the surface of the wood. The fungus inside the wood will continue to grow and cause the wood to deteriorate further.

You may have some limited success with bleach if you use it on wood that you are sure that has just begun to rot. But there is no guarantee of success even in this scenario.


Bora Care - 1 Jug Natural Borate Termite Control NI1001 by Nissus - 1 Gallon
Natural Borate Termite Control (Image: Amazon)

If you suspect that wood rot is starting, you need to take quick action to ensure that it doesn’t become irreversible. You can easily treat wood rot by applying borate.

Borate is the generic name for a compound called Disodium Octoborate Tetrahydrate, also known as SBX (DOT) which offers protection against decay, termites, and fungi.

Boron is the active element in DOT. The advantage of using DOT is that it not only kills the fungus, but it dissolves in water, so you get a better penetration to kill the fungi within the wood as well.

Ethylene Glycol

Alliance Chemical High Purity Ethylene Glycol 100% - Electronic Grade - One Sealed Gallon Jug
Ethylene Glycol 100%

Ethylene glycol is the compound that makes up antifreeze. It has a similar action to borate and is effective against different types of rot other than dry rot. The earliest use of glycol for wood was as a wood stabilizing agent. Today it is used extensively for treating wood rot, for example many boat owners use it to protect old wooden boats.

The advantage of glycol over borate is that it penetrates rapidly through paint and varnish, but doesn’t damage the finish. The will also be no discoloration even if for light-colored wood like pinewood. Even if you aren’t able to perform repairs immediately, you can soak the wood in glycol to prevent the wood rot from progressing. Be sure to carefully read the instructions and take safety precautions when using these products as they are hazardous to human health.

Tim-bor Professional Insecticide and Fungicide

Tim-bor Professional Insecticide and Fungicide, 1.5 lb. bag
Tim-bor Professional Insecticide and Fungicide,

This powder needs to be mixed with water and can then be applied to wood structures including fences, decking, sheds and other outbuildings. Active ingredient: Disodium Octaborate Tetrahydrate 98%

US Navy-Based Home Brew Water Solution of Borates

As per information provided by the US Navy, you can dissolve 60% borax with 40% boric acid in water. If you make a mixture of water 65%, borax 20%, and boric acid 15% by weight, you will get a solution of 15.8% borates. Heat the solution to dissolve the ingredients more easily and faster. These ingredients are readily available at a supermarket or drugstore. Some people make this DIY compound as a more affordable option compared to the Tim-Bor mentioned above, although you have to factor in the hassle of cooking up the solution and the safety concerns.

Home Brew Glycol-Borate Solution

You can make this solution by mixing glycol antifreeze 50% with borax 28% and boric acid 22%. Use a thermometer to monitor the temperature and boil the mixture until it reaches 260°F. The solution has a borate content of 26%. On cooling, you can store the solution in the refrigerator until you need to use it.

How to Prevent Wood Rot

Here are a few useful tips that will prevent wood rot from occurring in the first place:

Use Preservative

Although it won’t prevent moisture, it will protect the wood from decay and rot.

Use Decay-Resistant Lumber

Some species of wood have a high resistance to rot. Although the expense may be more, there will be less risk of wood rot developing. A few decay-resistant varieties of wood are teak, rosewood, redwood, black locust, and oak.

Do Not Install Wood Too Deeply

Generally, the deeper you go, the moister the ground gets. Hence, it is a good practice not to drive stakes or posts into the ground deeper than 15 inches.

Dehumidify the Air

In locations where the humidity is likely to be high like in a basement, run a dehumidifier. This will keep the air dry and there will be less tendency for moisture to develop in wood, thereby inhibiting the development of rot.

Keep Gutters and Water Outlets Clear

In the case of installing wooden structures outdoors, keep them away from gutters and water outlets (like washing areas). If the wood is constantly getting splashed, the moisture will soak into the wood and promote the growth of wood rot.

Keep Humid Areas Well-Ventilated

There are some places which are always moist like a bathroom or a laundry room. Install vents and exhaust fans to get rid of the humid air which will get replaced with cool, dry air.


As a woodworker, you will be bound to come across cases of wood rot. It is useful to know about the different kinds of wood rot and the chemicals you can use to prevent it.

Will bleach prevent wood rot? Yes, to some extent, but there are other chemicals and even home remedies you can use as well that can be more effective.

However hard you try to treat wood rot, it is like cancer to wood. The best way is to prevent it by following the best practices we have outlined here to prevent wood rot from occurring.

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