When purchasing a new summerhouse, the base for the building is one of the most important decisions to be made. A solid foundation will keep the structure in place for years to come and maintain the overall integrity of the building.
Once you have decided to invest in a summerhouse, it’s important to consider the type of base that will be used. A large number of summerhouses use timber frames to raise the building and provide a level base. But if you already have a level area in place in your garden, it can be tempting to use that instead and avoid any unnecessary costs.
The problem with pre-existing bases is that they are often not suitable to hold a heavy building such as a summerhouse. Countless examples can be found on the internet where the installers have turned up and an unsuitable base has led to the customers new garden building being unable to be installed. This includes bases that are not as even as they look, an area that is too small for the overall building and even an unstable structure.
Can I put my summerhouse on decking?
Yes, a summerhouse can be placed on decking, provided the area is properly treated and prepared in advance. If you already have decking installed, repurposing it as the base for a summerhouse is a low-cost option that will reduce time and effort during installation. If you do not have existing decking, we would recommend using a concrete base where possible for less maintenance and its ability to withstand the UK weather better.
Between the decking timber and the ground below, a weed-proof membrane will be needed to protect against any growth underneath. The gap below the decking allows air to circulate and prevents damp rising and causing damage to a summerhouse floor. Any decking should be substantial enough and feature adequate support to hold the weight of a several hundred-kilogram summerhouse. Only small summerhouses are suitable for use with decking. Many existing decking structures will need to be reinforced to support a summerhouse.
Timber decking should feature pressure-treated wood. This provides protection against rot and damp during the colder months of the year. For existing decking, it’s a good idea to clean the timber and apply fresh treatment before installing a summerhouse. Using decking as a base will also require regular maintenance, usually once a year.
Where decking works great is to create a verandah around a summerhouse. A large seating or entrance area can be installed outside to create a larger space for entertaining.
What makes a good summerhouse base?
- Smooth and level
If there was one tip I could give to any new summerhouse owner, it would be to make sure that your base is 100% level before installation. Garden buildings are made in factories to very tight tolerances. A slightly uneven base, even just on one side, will mean the tolerances are no longer attainable and the summerhouse may not go together properly. This could lead to gaps in the walls where the panels will not join up evenly and the building will not be watertight. The wood can also become strained over time which could lead to warping that makes windows and doors difficult to open.
Getting the footprint of your base correct will avoid any issues with installation and stop damp around the building. It’s recommended to make the base of a summerhouse slightly larger than the building’s dimensions. Using the exact dimensions of the building leaves little room for error which could be caused by your measurements or the summerhouse dimensions being slightly out. Too large and this creates a perfect location for water to puddle up around the sides of the building which can lead to damp over time.
- Firm and solid
Even a small summerhouse can weigh hundreds of kilograms. And that’s before all of your furniture is inside. The base needs to be solid and able to hold the weight of the building for years into the future. The last thing you want is the base falling apart when you are inside. For wood bases, enough fixings are required to support the structure and keep it firmly in place.
Which base do we recommend?
Where possible, we prefer a concrete or slab base. Concrete provides a solid, stable and smooth base which is perfect to install a summerhouse on top. For a smaller building, the base can be completed as a DIY job over a weekend. A concrete base will require enough time to dry and should be completed several weeks before installation. A damp-proof membrane is also used to protect the building against moisture rising.
Paving slabs also make a great option, and the rainwater can easily run off in between the gaps. The installation is similar to a concrete base and a sub-base is required before laying the slabs.
Overall, decking is suitable for use as a summerhouse base. But there are many precautions to be aware of including ensuring it will be able to support the weight of the building. Where possible we recommend a concrete base.