Quick guide to preparing the ground area for your GOS pergola

The simple steps needed for preparing the ground for your pergola build.

To be on the safe side, a pergola needs a stable foundation. The pergola must be fitted on to a solid surface and beneath the finished surface must be something for the pergola to be secured safely such as a concrete pad. In this blog you can find out what types there are and which may be the right option for your Gardens of Style Luxury Pergola.

Why is important to lay a solid foundation for your pergola?

A solid foundation is essential for a stable and level base for your pergola. This not only simplifies assembly but also guarantees the necessary stability of the structure. Placing your pergola on sloping ground can result in uneven pressure that it may not be designed to handle.

The consequences to not preparing for your pergola correctly:

• The pressure on the screw connections is too high, it can cause damage.
• The integrated gradient may be negatively influenced, so the water cannot drain properly. 
• Accessories such as screen blinds cannot be installed correctly. 
• Your Warranty conditions may be affected.

It also has disadvantages in terms of looks - and no-one wants a wonky pergola!

Is a foundation required for a pergola?

Pergolas come in various sizes and weight categories, leading to uncertainty regarding the necessity of a foundation. It is recommended to understand the relevant building regulations for the intended construction site to determine if a compacted soil with gravel and terrace slabs is adequate. For each of our pergola types, we recommend concrete pads of approx 40x40x40cm beneath any tiles, to be dug in underneath the chosen area; where each leg of the pergola will be fixed.

Building regulations: You do not need a building permit, however, there are a few things to consider and can be found in the article:

Is planning permssion needed when considering a GOS pergola in the UK?

In certain scenarios, a foundation may not be required. This is applicable if your terrace is already constructed on a foundation, allowing for secure attachment of the pergola using anchor bolts (expansion bolts).

The main and safest thing to know is what foundation you are building your pergola upon.

Check the subsoil

The condition of the subsoil plays an extremely important role and should be checked first. Is it pure, solid topsoil or loose, sandy soil? Is the subsoil possibly crisscrossed with roots that make it difficult to build the foundation?

To do this, simply do a test excavation to be sure!

Utility connections for your pergola:

Do you require power and water connections in your pergola for amenities such as an outdoor kitchen, hot tub or lighting/heating?

• The empty pipes required for this should already be integrated during the construction of the foundation. Except for point and strip foundations, they can be retrofitted. 
• Consider whether you do this work yourself or whether you need to hire a  specialist.

Size of pergola foundation needed

To properly plan the foundation, consult the dimensions provided in the floor plan of your upcoming Gardens of Style Pergola. We will always provide a floorplan indicating where the floor plates of the pergola will sit based on your chosen size and orientation, the floorpan can also be viewed on the relevant product page on our website. This allows you to prepare the foundation in advance, avoiding the need to store the pergola for an extended period. If required, a date for installation/assembly will be arranged with you at point of purchase.

Foundation type

Depending on the given conditions, different foundation variants are possible. Consider the below advice alongside your own pergola space.

• A slab foundation made of path slabs with concrete pads underneath each corner, is often sufficient for small pergolas.
• For larger models, there should be point or strip foundations.
• On unstable ground, a continuously closed concrete slab is recommended
• If the ground is stable, the screw foundation, which can be built relatively quickly, is an option.

It is a good idea to choose your pergola size before doing any groundworks however if you have already laid the patio/deck then we do advise for you to check what is beneath the surface. Is it secure enough? Type1 or sand would not be suitable. Composite decking without something solid below would not be secure enough, unless you already have structural beams underneath where the footplates will sit. If this is the case, installing would be successful as long as all footplates are sitting on structural beams wide enough for the footplate to be bolted into fully.

See video below for a example of preparing concrete footings onto a lawn, ready for a pergola.

Materials Used in Video:

Postcrete Fast Setting Mix

Postcrete Form Setting Tube 12" x 48"

Hillman 5/8" x 12" Anchor Bolt

Should you have any questions before completing groundworks or booking a pergola installation please speak to our team by calling

5% of any Pergola sold here at GOS will be donated to Motor Neurone Disease Association via Work for Good. Help us support people affected by MND.