About Our Treated Timber and C24 Joists

Our range of treated carcassing is straight, smooth and consistently sized construction timber. It has eased edges for faster handling on site.

We stock structurally graded C24 which complies with EN14081-2 and is pressure preservative treated with Tanalith E for a durable finish.

Available in a range of finished sizes and lengths.

Other treated timber including battens is pressure preservative treated with Tanalith E and our roof battens comply with British standard BS5534.

When do I need Treated Structural Timber?

If the timber is going to be placed in an area where attacks from external problems such as moisture or fungal attacks, are likely to cause major problems, then we strongly recommend purchasing treated structural timber.

For all the following applications, we generally recommend using a treated structural timber:

Roof Rafters, Timber Framing, Ceiling Joists, Floor Joists, Deck Joists

What is C24 Graded Timber?

C24 timber has been graded to a higher standard than C16. It's a premium piece of timber that can handle higher loads and wider spans. C24 grade can only be achieved by importing timber from areas where the climate forces a slower growth rate and hence a tighter grain. The tighter the growth rings of the wood, the better-quality piece of wood that you are dealing with.

It is a better-quality structural option because it can take up to 50% longer for these timbers to grow, meaning that they have more growth rings. The more growth rings a piece of wood has, the higher its overall density, which in turn means that it has greater natural durability and improved stability.

What is Tanalith E?

TANALITH E pressure-treated timber is timber that has been impregnated with TANALITH E wood preservative under controlled conditions in a vacuum pressure timber impregnation plant. TANALITH E is a water-based wood preservative that contains copper and proven organic biocides. When impregnated with the timber the preservative components bond with the wood structure and cannot easily be removed. TANALITH E pressure-treated timber has long-term protection against fungal and insect attacks, for both in and out-of-ground contact, interior and exterior applications when treated to the correct end-user specification. TANALITH E pressure-treated timber has an initial natural green colouration. Upon external exposure, the green colour slowly weathers to a warm, honey brown and in the longer term becomes a natural silver grey. This weathering process does not indicate any loss of preservative protection.

Is pressure-treated wood safe for indoor use?

Yes! Pressure-treated wood is completely safe to use for interior applications the only exceptions would be as cutting boards or countertops.