Untreated C24 timber is strength graded structural softwood with no preservative, kiln dried to 20% moisture content or below. It is the standard choice for dry inside work: floor joists, ceiling joists, rafters inside the house and stud walls. We stock 7 sections from 47x75mm to 47x225mm, sawn regularised with eased edges, from £4.48 a length. Collect from our Bridgend yard or order online.
Untreated timber has not had any preservative added. Our untreated C24 is kiln dried to 20% moisture content or below, so it is stable and ready to use, but it has no protection against rot or insects. That makes it right for inside jobs that stay dry.
Can I use untreated timber outside?
No. Untreated timber will rot if it gets wet and stays wet. For anything outside, or anywhere it could get damp, use pressure treated timber instead. Our treated C24 is the same grade with preservative added.
Should I use treated or untreated C24 for joists and stud walls?
For dry inside work like floor joists, ceiling joists and stud walls, kiln dried untreated C24 is the usual choice. If your drawings or building control ask for treated timber, follow them. If you are not sure, call the yard on 01656 745959.
What does kiln dried to 20% mean?
The timber has been dried in a kiln until no more than 20% of its weight is water. Drier timber shrinks and twists less after it is fitted, so your walls and floors stay straight. Let it sit on site for a couple of days before fixing.
Questions about sizes or spans? Call the yard on 01656 745959.
