Sawn and Treated Timber – Everything You Need to Know.

What is Sawn and Treated Timber?
Softwood timber (normally redwood timber) that has been pressure impregnated with a preservative to protect the timber against insect attack and fungal decay.

What is timber treated with?
Our timber is pressure treated with Celcure a mix of copper and organic co-biocides to provide optimal protection against insect and fungal decay attack.

What is the difference between treated and untreated timber?
Untreated timber (sometimes referred to as sawn) is in its natural state. and therefore offers no protection to environmental conditions. Treated timber is pressure impregnated to guard against environmental conditions.

MP Moran is a long-established supplier of Sawn and Treated Timber (sometimes called Rough Sawn Timber or even Carcassing Timber) located in the London and Hertfordshire area, providing C16 and C24 graded timber for commercial or domestic projects. If you need treated timber prices this is the place for you to browse an extensive product range in C16 and C24 strength grades. We deliver across; London, Bedfordshire, Buckinghamshire, Hertfordshire, Essex, Berkshire, Surrey, West Sussex, East Sussex and Kent.

Our treated timber and carcassing timber are sourced from some of the leading manufacturers and suppliers in the industry, we work hard in building up strong relationships to make sure that our customers get the highest quality product to ensure longevity in whatever they are doing.

Treated timber is available in a wide range of sizes, making it ideal for both smaller and larger projects. Each timber size is regularly price checked to make sure all of our customers are getting the best, competitive rate – saving London and Hertfordshire builders money as much as we can.

Treated Timber

Available on a next day delivery basis, our treated timber can be delivered to the door of your project, making sure that none of your deadlines are put on hold due to you waiting on additional materials. Our award-winning transport fleet is made up of the most up to date vehicles, with our staff specifically trained in health and safety to ensure that these large timber products are transported safely. What’s more, we also look to helping our environment and aim to reduce our carbon footprint as much as possible.

If you would like more information on any of our treated timber, or you would like to find out more about any of our services and company goals, please get in touch with a member of our team either in one of our branches or by calling 0843 600 5566.

What is Treated Timber?
Our treated timber is pre-treated with Osmose Naturewood. By specifying timber that is treated with the appropriate end use it will ensure its long life. Our treated timber products meet a variety of British and European standards, the Highways agency and NHBC. The treatment preserves the timber making it useable for external, moist and wet conditions. Plus is guard’s timber against attack from various

Treated Timber

The types of preservation system available are;
Protim – an organic system that pressure treats timber used in construction projects, where the required protection is to Class UC1, UC2 and UC3.
When using Protim in an external environment it should be coated with an external coating.
Celcure preservation system is used for wood that has been treated with an Osmose preservative system. It also preserves the timber to Classes UC1, UC2, UC3 and UC4.
MicroPro – is a preservation system is also used for timber that has been treated with Osmose. It again protects the timber to Classes UC1, UC3 and UC4

Treated Timber Class Table.
Class 1 – Above ground, covered. Permanently dry, risk of insects.
Class 2 – Above ground, covered. Occasional risk of getting wet.
Class 3a – Above ground, coated. Exposed to frequent wetting.
Class 4 – In contact with the ground or fresh water. Permanently exposed to wetting.

What is the Timber Preservation Process
1. Timber is transferred into a treatment vessel
2. A vacuum pulls the air out of the vessel
3. Osmose preservative then fills the vessel
4. The vessel is pressurised forcing the preservative into the timber
5. The preservative is removed, and a final vacuum is applied
6. The timber has now completed the Osmose preservation process

Treated timber guards against attacks by these wood boring insects and fungi.
1. Common Furniture Beetle
2. Wood boring weevil
3. Death Watch Beetle
4. House Longhorn Beetle
5. Termites
6. Dry Wood Termites
7. Subterranean Termites
8. Cellar Fungus
9. Pore Fungus
10. Dry Rot

Sawn Timber

What is Off Sawn Timber and Rough Sawn Timber?
A trade term for sawn timber is ‘Off Sawn Timber’. This simply refers to the tree trunk being sawn by a large band saw leaving sawn sections. The sawn sections are obviously rough in finish…these sections are called Off Sawn Timber.

Another trade term is rough sawn timber, which means exactly as above…where the tree trunk is cut by a band saw, giving it a rough ‘unfinished’ surface. The surface is then finished by sanding to create a smooth surface finish.

Rough Sawn Timber should not be used for structural purposes as it has not been strength tested / graded for this purpose.

What is Graded Timber?
Timber is strength graded to C16 or sometimes C24 which is the equivalent to BS EN 14081 and BSEN519:1995
C24 is a stronger grade than C16.
C16 graded timber kiln dried is mainly used on internal floor joists and roof joists. Online we offer lengths up to 6.0m – although longer lengths are available on request.
C16 treated timber is specified when the strength is required in an outside environment. Treated C16 timber is often found in roof rafters, timber framing, ceiling joists, floor joists and deck joists and other garden buildings.

Graded Timber

What are the Standard Lengths of Timber?
Sawn timber comes in these standard lengths and then plus thickness (mm) listed in the table below;

1.8m / 2.10m / 2.40m / 2.40m / 2.7m / 3.0m / 3.30m / 3.60m / 3.90m / 4.20m / 4.50m / 4.80m / 5.10m / 5.70m / 6.0m / 6.30m

Note; Not all of these lengths will be available to stock.

Sawn Size is the dimension after the timber is sawn, but not yet planed to a smooth finish.

Finished Size is the dimension after planning, so always a few mm less than the sawn.

Some timber merchants / tradesman still works in inches which is why the size chart covers both options.

What Lengths do 4.2 come in?
4×2 Inches is also 100mm x 50mm – these dimensions would be the sawn dimensions or the nominal dimension, prior to the timber being planed to create a smooth finish. The finished dimension would be around 95-97mm x 47mm

4×2 is generally available in; 3.0, 3.6, 4.2, 4.8 metre lengths.

What price is 2×4 timber?
One of the common question we get asked as 4x2in timber or 100x50mm
Price can be obtain online.

What is Treated Timber used for
The location of where the timber is going to be used determines how you should use it.

Internal Use Permanently Dry
The timber is commonly used for constructing Pitched Roofs, Floorboards, Architrave and Skirting, Upper Floorboards.

Internal: Some Wetting
Tile battens, timber-built frames (like stud walls), timber in roofs where condensation could be a problem, timber in flat roofs, ground floor joints and upper floor joists.

External: Subject to frequent wetting
Roof soffits, fascia’s and bargeboards, cladding, guttering and external loading timbers

External: Fencing and boarding, agricultural use but not subject to ground contact, landscaping and decking use but again not in contact with the ground.

External: Permanently in the ground or in permanent water contact
Fencing posts and gravel boards, agricultural use and in contact with the ground, retaining walls of earth (like sleepers), playground areas and gates.

External: Permanent ground and water contact
Main use: piers, jetties, sea defences and ship building.


Are you looking for high quality sawn timber? At MP Moran we supply a range of high quality sawn timber across London, and Hertfordshire. Our timber is suited for both commercial and domestic projects. All of our sawn timber is available both online and in our branches across London and Hertfordshire.