What Sort of Base Do I Need for The Outdoor Classroom?

This is perhaps one of the most commonly asked questions from our customers when we are discussing build requirements for their outdoor classroom or undertaking a site visit. A lot depends on the site itself and a number of other mitigating factors – whether it is level, what type of existing surface the feature will be installed onto (eg grass/tarmac/concrete etc), and if the area is prone to flooding and rainwater retention etc

But in the majority of cases, we install a timber sub-frame levelling base as per below image. If the ground is not exactly level, we can get the floor to be so by setting the posts into the ground at different depths over the span of the area. With this system, we can typically cope with a fall of no more than 350mm over a 5m area. If the fall is greater than this, then some pre-excavation and levelling work will have to be done (by others) before we come to install on site. Below the timber sub-frame base is a geo textile membrane to stop the grass growing through.

Once this base is installed, we then build up the walls for the outdoor classroom and install the decking floor. So that you cannot see this once completed, we install a decking timber section as skirting around the base which also gives the building quite an appealing aesthetic feel to it. If there is indeed a fall over the area, then we compensate for this by adding extra decking panels around the skirt which our experienced joiners do on site as they are cut to size.

If the ground conditions are quite boggy and prone to flooding, then we have used a ground screw pile system in the past. These are essentially giant screws which get drilled and secured into the ground – without the need for laying any concrete – and onto which are fixed the timber bearers of our base. The outdoor classrooms then sits up off the ground and does not come into direct contact with any sitting water (see photo below of this system)

Last but not least, it is possible to lay a concrete base. Typically this is undertaken by local contractors as they tend to be way more competitive on price and if a school does opt for this, we are able to provide dimensional drawings.

For our comprehensive range of outdoor classrooms, please visit Hideout House Outdoor Classrooms

 or contact us on 01832 275902 and email: info@hideouthouse.com