Treated Carcassing Timber

Choosing Treated Carcassing Timber

Carcassing timber is construction timber used for framing and structural applications such as wall studs, floor joists and roof members. Choose the section size, strength grade and preservative treatment to match your project specification.

C16 and C24 Strength Grades

C16 and C24 are timber strength classes, not treatment ratings. C24 has higher specified strength and stiffness than C16, but the required grade depends on the design, loads and spans.

Check each product listing before ordering. Where a product is described as C16/C24, confirm the grade available if your design specifically requires C24. Do not substitute a different grade or smaller section without approval from the person responsible for the structural design.

Timber Sizes and Lengths

Check whether the dimensions shown are nominal or finished sizes. Machined timber can have a smaller finished section than its nominal description, which matters when matching existing timber, connectors or a structural specification.

Plan your cutting list around the available lengths, allowing for saw cuts and waste. Confirm the finished dimensions where a precise fit is required.

Matching Treatment to the Job

Preservative treatment and strength grading serve different purposes. Treatment helps protect timber against biological deterioration in the conditions it is specified for; it does not make every treated product suitable for every outdoor application.

For decking subframes, ground contact or other exposed uses, confirm the required treatment Use Class before ordering. Do not assume standard treated carcassing is suitable simply because it is described as treated.

For timber deck joists, posts and beams, the Timber Decking and Cladding Association recommends Use Class 4 treatment, even when the timber is above ground. Ask us to confirm the specification of the selected product.

Planning Your Timber Order

Before ordering, have the following details ready:

• The specified strength grade and treatment requirements.
• The required finished timber sections.
• The lengths and number of pieces needed.
• A cutting list, with an allowance for cuts and waste.
• The specified connectors and fixings.
• Your delivery postcode and any access restrictions.

For load-bearing work, have timber sizes, spans, spacing and connections confirmed by a suitably qualified designer before buying materials. Our team can help with product selection and quantities against your specification.

Fixings and Cut-End Treatment

Choose fixings and connectors to match the design, timber treatment and exposure conditions. Browse our joist hangers and brackets, and follow the connector manufacturer's requirements for compatible nails or screws.

Follow the timber supplier's instructions for treating freshly cut ends with a compatible end-grain preservative. Brush-on treatment is not a substitute for buying timber with the correct original treatment specification.

Help With Your Materials Order

Send us your timber schedule or cutting list, including section sizes, lengths, quantities, strength grade and treatment requirements. Let us know whether you need collection or delivery.

Call 01452 300159 or email sales@nickstimber.co.uk to discuss availability and your materials order.

Collection and Delivery

Collect from Nick's Timber, Canada Wharf, Bristol Road, Gloucester GL1 5TE, or arrange delivery to a supported postcode.

Check our delivery areas, charges and estimated times. Contact us to confirm stock and collection availability before travelling.