How To and How Often to Treat Your Garden Room & Offices

There are many types of preservatives available for garden offices and summer rooms which range from fully pressurised tanalised treatments down to water-based treatment. In the past one of the favourite treatments was creosote, often supplemented with old engine oil. This did a great job protecting the timber from the harsh weather but had to be reapplied from time to time. This had a distinctive smell, quite strong, which tended to linger for quite a while. Not ideal if you had treated the inside of your garden building which you wanted to work in. Thankfully, improved safety rules were introduced in 2003 as it had proved dangerous to use and from 30th June 2004 it is illegal even to store it or keep it in any form so if you have any in your shed you should dispose of it responsibly. A new substitute Crecote has been introduced for people who wish to get a similar effect.

On cheap garden rooms, you will find that a water-based preservative is commonly used and is mainly serving the purpose of a base coat, for your second coat to be put on. The water is a carrier for the chemicals and helps the compound to adhere and react to the wood of the garden building, and protecting it to a certain degree. This can be dipped into a bath of this treatment or painted or may be sprayed onto the panels.

Sprit or solvent-based preservatives are the preferred and better method of applying treatment onto timber. The solution again is a carrier for the chemicals and works far better than the water. The spirit treatment or solvent helps greatly and gives better protection to the timber. Yet this can be sprayed on (but if done so protective equipment should be worn), sprayed on or dipped onto the timber house. Very few people dip their building in this dues to the possibility of reactions to the operatives doing the dipping.

For a better type of treatment, you need to look at the oil-based option. The oil holds the chemicals and bond the chemicals into the wood. The oil as it soaks into the timber gives it a certain amount of ‘give’ helping with the natural movement of your building. Tanalising, or pressure-treating, is the very best you can do for your timber. The tanalising process consists of the wood being put into a sealed vat. And the Tanalith E fluid is forced into the wood under pressure.The pressure ensures that the preservative soaks in a great deal further than just brushing or spraying. The result of this is that the timber should be protected against rot for 15 years. On the Platinum offices and garden rooms, the cladding is pressure treated as standard.

The pressure treatment also protects against fungal and insect attacks giving your new building a long life. The appearance of the timber is quite attractive, having a slight natural green tint to the wood which can blend into the garden. However, you can add a colour treatment to the wood if you wish. This treatment is ideal for any building in an enclosed space, i.e. where treating would prove difficult or where you like the idea of very low maintenance.

One the very best and most popular timber treatment is offered on all the Platinum buildings and is a Valtti exterior paint and wood stain finish. You can add colour as well as the ultimate protection to your building, with their choice of options, either a durable, low maintenance paint or a semi-transparent wood stain applied to the assembled panels of your building before delivery. The option will include the exterior of the building having two brush applied coats, giving your building the best start in a long life.There are three options
1/ Valtti Opaque is a semi-matt microporous high performance flexible waterborne paint for wood. Valtti Opaque offers good weather resistance, great flexibility, and has an extremely durable low maintenance finish. With excellent colour stability and dirt repellency.
2/ Valtti Colour is a full matt, low build solvent-borne translucent wood finish. Valtti colour absorbs well into the timber and enhances the natural beauty of the wood. This semi-transparent wood finish protects the wood surfaces from the adverse effects of moisture and UV light, without covering up the beautiful wood grain
3/ For a more natural-looking finish, Kesto Plus is an extremely durable exterior wood stain option. With a semi-matt finish, leaving a water repellent wood protecting surface with good UV protection. Kesto Plus protects the wood against weathering and the adverse effects of moisture and sunlight. With a slight oak tint, this semi-transparent finish will give a natural, durable finish.

On delivery, you would be left with a touch-up can of the colour chosen for future maintenance and where any possible shrinkage lines may appear. It might not be cheap (but nothing of value is), but you will end up with a delightful building, fully protected and in a choice of colours to suit you. That’s well worth thinking about.

Click for downloadable leaflet about these treatments

However, whatever treatment you have it is important to keep an eye on it to ensure that you retreat when necessary. The only other treatment which the tanalised summer house needs is a water repellent treatment, such as Thomsons WaterSeal. This would stop any dampness coming through if the building was subjected to torrential rain. (the timber is treated against rotting and is not a water repellent in its own right)All buildings should be re-treated shortly after delivery. The water-based treated building should be re-treated within four weeks of delivery, ideally, and then every 2-3 years, depending on the weather conditions. The same would apply with the spirit or solvent-based treatments as well as the pressure treated buildings if you want the longest-lasting results. With the oil-based treatment after the building has its first coat, you could get up to 4-5 years before anything needs doing again except for any sides facing into the weather.

In my view, I would not recommend any of the water-based treatments for the topcoats. I would only recommend spirit, solvent or oil-based preservatives despite what the cheap building manufacturers may say. Water-based treatments are fine for base coats or fences, nothing else.

Some manufacturers claim to offer a 10-year guarantee, even with the water-based treatment; however, like most things in life, this is not as good an offer as it seems. There are very severe conditions stating that if your building is not treated EVERY year, then the guarantee would be null and void. This means that the treatment they are applying only last for ONE year and any further protection is only coming from the treatment YOU have to use every year.A WORTHLESS warranty so DON’T be taken in by them. The best thing (or worse) is that you will be fortunate to find any details of the conditions on those sites.

With the benefit of my 40 years in the timber buildings business, I hope that the above advice is useful for you to understand how to get the best out of your new acquisition. Over the years there have been many improvements and changes to the treatments available, some good and some bad, however, if you look after your building, they will last many many years.

Regularly oil any moving parts such as locks and door or opening window hinges.

Keep an eye on the condition of the roofing felt. If it starts to deteriorate, replace it with a good quality replacement – if water starts to seep into the roof, this is the beginning of the end for your garden building. If you are in any doubt, or would like any advice, please telephone or CONTACT US for further assistance.

You may feel you want to put it off, but your garden office does need treating from time to time to ensure a long life. By following our advice, you won’t need to do this more than every 2 or 3 years. This action will ensure your outside building can be protected against everything the weather can throw at it.Treating a building can be a messy affair, indeed, if I am doing it, so the advice is to wear old clothes which can be thrown away if too severely stained. Always bear in mind that many treatments can irritate the skin due to the chemicals in them which help to preserve the wood. But try not to splash the treatment and always take your time. If you do get any treatment on your hands, face or skin ensure you wash this off straight away.

Try to treat your new building, if you have the opportunity before it is erected, certainly, if it is one on the cheaper ones obtainable on the web or at your local DIY superstore. You will find the treatment they use is just like coloured water and does not give any protection to your building. You can ensure that all parts of the building are treated by doing this before assembly. Whilst, when assembled these parts won’t get any weather, it will not do any harm if you can do so. Stop moisture getting into the wood by always applying the treatment liberally.

You will find that PAR (prepared all round) timber such as shiplap or T&G wooden buildings will have a smooth finish, and you can paint the treatment on very quickly. However, it is best to use at least two coats, as the treatment will not soak in too well. If your building is a feather edge or made from sawn finished timber, you will find the treatment will soak into the wood and will take longer to do. However, you will know that this treatment will last the longest due to the treatment soaking into your timbers.

You can choose to use a spray to apply preservative but, if you do, it is vital that you wear a face mask and, ideally, goggles to ensure that the fine spray does not get down your throat or on your eyes. It some instances where it is awkward to get to, such as between the building and a fence or wall a spray is a good idea. By getting on the roof, you can reach down into the gap and liberally spray the treatment onto all exposed areas.

After you have finished treating you can take a break from these duties for, generally at least 2 or 3 years. You will find that the sides of your summer building facing into the weather, i.e. the sides which get the sun shining onto it or the rain splashing against it will need treating more often. It will become apparent by the sides fading in colour. Never wait until signs of damp start getting into the wood as this will be the beginning of the end for your garden building.

My advice is based on 40 years in the garden buildings business. For further advice about what type of treatment to use take a look at our other articles.