Make sure all that lovely timber stays in tip-top condition after delivery. Here is a guide to storing your timber properly – preventing any compromises in its integrity and performance.
There are many problems that can result from poor storage of timber onsite. Increased wetting of the timber, for example, will lead to a higher moisture content. Defects will occur in the timber because of this, such as shrinkage, leading to the product being unfit for purpose.
Damage to metal fixings is another risk – metal plates International Timber on roof trusses can be easily damaged if timber products aren’t stored correctly.
Moisture is not your friend
Damp and timber are not a good combination. A timber product should arrive on site with the right moisture content, and changes to that moisture content can give you all sorts of problems.
- Check the timber’s moisture content is right on delivery
- Store timber products inside the building where they are going to be used
If the latter isn’t possible, try to provide good quality temporary covering. If you have to store timber products outside, under cover, make sure there is adequate ventilation to help prevent changes to moisture content.
Be cautious when storing timber products in newly plastered buildings or near newly concreted floors, as the moisture in the atmosphere could be high. Use temporary storage in this case – a garage or shed perhaps – but make sure it has good ventilation. Ideally, schedule the timber to be delivered when the building has dried out.
Image © Binderholz: works at Dalston Lane for Waugh Thistleton’s Dalston Works, London, completed in 2017.
Storing your carcassing
All timber, even carcassing, benefits from good covering and storage. If you have to store carcassing outside, make sure you store it on dry, even ground that doesn’t retain water. If possible, spread the area with gravel or sand. To help prevent warping with changing conditions, stack the timber flat on equal sized bearers of, say 75mm x 75mm. Put one bearer towards each end of the timber and one in the middle.
Use a waterproof cover over the timber, but allow air circulation around the timber. This will not only keep it dry but will also protect it from direct sunlight, which could warp the timber.
Joinery or manufactured and factory-finished timber products
These products, such as windows and doors, are expensive and can be easily damaged. Typically delivered direct from the factory ready for installation, these products will have been manufactured to a precise moisture content and wrapped to protect the finish.
Take extra care when storing them under cover. Without unwrapping the product, check there has been no damage on delivery. Where possible, store in a well ventilated area, preferably the building they are to be installed in once the building has properly dried out.
If this isn’t possible, use well ventilated temporary storage, such as a garage or large shed with some form of heating control to maintain the factory moisture content. Store vertically, taking care to avoid damage caused by the ironmongery. And store in the order you’ll be using the product.
Sheet materials
Ideally, store these in similar conditions to factoryfinished products. Do not store interior quality sheet materials outside. If possible, always store them flat on equalsized bearers positioned at maximum 600mm centres. This will help to keep the sheets level, and away from direct ground contact. Keep bearers horizontally aligned to avoid any distortion of the boards.
If storing materials thinner than 6mm, use a thicker sheet of material, say 18mm, under them to provide additional support. When storing large numbers of sheet materials, split them up into 10-15 boards, stacked in line with bearers. This will provide even more protection against distortion, especially if they are not going to be used quickly.
When using factoryfinished and speciality sheet materials indoors, try to store them as described for a minimum of 48 hours in the dried-out building they are going to be fixed in.
Image © Knox Bhavan: March House (see ‘After the Rain’ feature in this issue)
Roof trusses, structural timber components and I-joists
As these are bulky items, schedule site deliveries so that you are using the products as soon after delivery as possible. Store them vertically with trestle support and bearers underneath the metal connecting plates. If you have to store then horizontally, ensure you use evenly sized timber supports to keep them off the ground, placing them underneath each truss node.
Cover and protect them, as previously described in this article. Take care to only lift trusses at the designated fixing points. Once fixed to form the roof, cover with felt as quickly as possible to provide additional protection.
Timber frame panels
Make sure these factory engineered components are stored side up on equal-sized bearers at even intervals. Cover and protect them as previously described.
Certified products
Try to store separately from your other site products to allow easier identification of the product. If you are the project manager, ensure that they have a valid chain of custody certificate.
Plan deliveries of factory-finished products to be ready when you want to install them
- Keep all timber products protected from rain, surface water and sunlight.
- Before work onsite begins, consider the type and size of indoor or undercover storage you might need.
- Check the moisture content of your timber products on delivery and report to your supplier if they don’t comply with the specification.
- Check products have been properly covered for transit from the factory or supplier, and there is no evidence of damage.
- Use the correct mechanical handling gear for unloading and storage and avoid edge damage, common on sheet materials.
- Leave any existing protective coverings in place.
- Ensure wet trades have finished before installing timber.
- Make sure the building is adequately ventilated throughout the process.
- Where there are openings, such as windows and doors, have them glazed or covered, even if only as a temporary measure temporary before final fitting.
Further information
Advice on stacking and handling wood products safely is available from the Health and Safety Executive (www.hse.gov.uk). Information on the care of trussed rafters can be found in the Trussed Rafter Association’s Technical Handbook and its Product Data Sheet No 3: Guidelines for the Storage and Erection of Trussed Rafters (www.tra.org.uk).
This article is taken for issue 2 of Designing Timber magazine. Read more of its articles here