Everything You Need Before You Buy.

Four essential guides covering UK planning permissions, precise measuring, foundation requirements, and how to care for your structure across every season.

Planning & Permission Measuring Foundations Maintenance

A pergola standing on a level, prepared base

The foundation is the single most critical factor in the long-term performance of your pergola. An incorrectly prepared base causes post misalignment, structural movement, and — in worst cases — voids your 15-year structural warranty. Get this right before anything else.

The Required Foundation Specification

Each post position requires a concrete pad foundation to the following minimum specification:

Width

Confirmed at point of order

Centred on post position

Depth (below ground)

Confirmed at point of order

Below finished ground level — not total depth including above-ground slab

Thickness / Length

Confirmed at point of order

Exact dimensions confirmed for your model and site

Concrete grade

C25 / GEN3 minimum

Ready-mix or site-mixed to BS 8500 standard

Curing time

Minimum 28 days

Before post installation or any load-bearing

Do Not Proceed Without This

Installing posts into under-specified foundations — including packed aggregate, lean-mix concrete, or pre-existing paving — will void your structural warranty. If your groundworks contractor proposes a smaller spec, refer them to this document.

Ground Surface Types

Existing concrete slab

If your existing slab is at least 150mm thick and structurally sound, your groundworks contractor may be able to core through it and pour the pad foundation below. Confirm with a builder before ordering.

Block paving or porcelain slabs

Lift the paving at post positions, excavate to 850mm, pour foundations, and relay paving around the post base after installation. A tidy finish requires careful planning of post centre positions before paving is lifted.

Grass / soil

Easiest for groundworks — no demolition required. Excavate, pour, cure, and then proceed with any landscaping or decking around the posts once the structure is in place.

Timber decking

Posts cannot be anchored to decking structure. Foundations must go through the deck and into the ground below. Requires careful coordination with your deck builder — discuss before ordering.

Consult a Builder First

We strongly recommend commissioning a qualified builder or groundworks contractor to assess your site and prepare foundations before your pergola is ordered. Pergola Pros does not supply or supervise groundworks — this is the homeowner's responsibility and must be completed before delivery day.

Timing Tip

With a typical lead time of approximately 3 months from order — around 1 month for manufacture and 2 months for shipping — you have ample time to get foundations poured and cured (28 days) before your structure arrives. Commission your groundworks contractor at the same time as placing your order.

Warranty Implications

Your 15-year structural warranty (Gold Series) and applicable warranties on other models are conditional on foundations meeting the specification above. In the event of a warranty claim, we may request evidence that foundations were correctly prepared — photographs of the poured concrete before backfilling are strongly recommended.

Structural movement, post lean, or frame distortion arising from inadequate foundations will not be covered under warranty. If you are unsure about your ground conditions — particularly in areas with clay soil, made ground, or tree root proximity — consult a structural engineer before commissioning groundworks.

The show pergola at dusk with its LED strips on

WANT TO SEE THE SHOW PERGOLA?

See the Engineering In Person.

Our single full-size show pergola is at our Sutton, Retford premises, and viewings are by appointment. Book a viewing on the showroom page, where you can send the dates and times that suit you. Or use the form below to send approximate sizes and photographs. We aim to return an initial budget estimate within a few working days; if it suits your budget, we then move to the detailed specification, CAD drawings and firm written quotation.