Custom Garden Trellis in Newmarket - The Full Process, Step by Step

Step One - the Initial Site Visit

Every custom trellis job starts with a proper look at what we are working with. Before any measurements are taken, we need to understand the fixing surface: is it brick, blockwork, render, timber fence panels, concrete posts, or a combination? Each surface has a different fixing method, and a quote produced without seeing the site often misses complications that add cost later.

During the visit we check the condition of the existing fence or wall that the trellis will fix to. Trellis added to a fence panel that is already soft or leaning will not perform well regardless of how well the trellis itself is built. If there are issues with the supporting structure, we flag them at this stage rather than after the trellis is up.

We also ask about any climbing plants that are going up or already established. A single clematis and a mature wisteria need very different structural capacity from the trellis behind them. Getting that conversation out of the way early means the timber section and fixings are specified correctly from the start.

Step Two - Measuring and Designing the Panel

Custom trellis is cut to your exact fence line or wall, which means every measurement needs to be accurate to within a few millimetres. Standard panels from a garden centre come in fixed sizes - typically 1.83 m x 0.3 m, 0.6 m, or 0.9 m - and homeowners end up with gaps at the ends or awkward cuts that look untidy and create unprotected exposed timber edges.

We measure the full run, note any obstacles such as wall ties, air bricks, downpipes, or gate hardware, and mark up the design. If the trellis is going above a fence line, we establish the post positions and confirm whether the existing posts can take the additional height load or whether post extensions or new posts are needed.

For more complex designs - trellis incorporating a gate opening, trellis wrapping a corner, or decorative panels with a specific pattern - we sketch the layout and confirm it with you before any timber is ordered. Changes at the drawing stage cost nothing. Changes once timber has been machined cost time and material.

Step Three - Timber Selection and Preparation

Once the design is confirmed, the timber is selected and machined to size. For standard custom trellis we use pressure-treated softwood graded to UC3 for above-ground use, with lath sections of 25 mm minimum width. For structural panels carrying heavy climbers, or where the customer specifies it, we use 32 mm or larger sections or switch to hardwood such as oak or sweet chestnut.

All cut ends are treated with end-grain preservative before the panel is assembled. This is the step most off-the-shelf trellis skips entirely - the treatment applied to the board during manufacture does not penetrate the cross-section exposed when the timber is cut, so untreated cut ends are the first place moisture gets in.

Where a painted or stained finish has been specified, the panels are coated before installation so every surface including the back face and the joints is covered. Trying to paint trellis in situ, against a wall or fence, always leaves unpainted patches that weather faster than the rest of the panel.

Step Four - Preparing the Fixing Points

Fixing preparation is often the most time-consuming part of the job and the part most likely to be underestimated in a hurried quote. Masonry walls need correctly spaced holes drilled at the right depth, with plugs rated for the load. Older brick, particularly pre-1950s stock, can be variable in hardness and the mortar joints may need extra care to avoid crumbling.

Where trellis is going above fence panels, the fixing method depends on the post type. Concrete posts can take a coach bolt through a purpose-made clamp or bracket. Timber posts can take a screwed bracket if the post is sound, or a through-bolt if there is any doubt. Simply screwing a trellis panel to the top of a standard 100 x 100 mm fence post without a proper bracket is a fixing that will work loose within a couple of years under plant load and wind pressure.

If the wall or fence has a damp-proof course or a cavity, we work around those - fixing through a DPC or into a cavity can cause problems that have nothing to do with the trellis itself. Where we see anything that warrants a conversation with a builder before we proceed, we flag it.

Step Five - Installing the Panels

Panels go up in sequence from one end of the run. We use packers to maintain a consistent gap between the panel and the fixing surface - typically 25-40 mm - which allows air to circulate behind the trellis and prevents moisture from being trapped against the wall or fence. Trellis fixed flush to a rendered wall will almost always cause staining and accelerated render decay at the fixing points.

All fixings are stainless steel or hot-dipped galvanised. Standard bright zinc-plated screws corrode within three to five years in outdoor conditions and stain the timber around them as they do so. On oak, stainless fixings are essential - standard steel causes deep black staining in the grain that cannot be removed.

Where panels meet at a corner or return, the joint is mitred or lapped and fixed so there is no exposed end grain on the outer face. Each panel is checked for level and alignment before the final fixings go in.

Step Six - Finishing and Clean-Up

Once the panels are fitted, we check every fixing point, test the panels for any movement, and carry out any touch-up to the finish coat at cut points or screw heads. If you have plants that were temporarily removed or tied back during the installation, we help guide them back onto the new structure.

All offcuts, packaging, and waste timber are taken away. The fixing surface - wall or fence - is cleaned of dust and debris from drilling. We do not leave a job until the garden looks better than when we arrived.

What the Customer Should Ask For

When comparing quotes for custom trellis in Newmarket, ask each contractor to confirm the timber section and treatment class in writing, the fixing method for your specific surface, whether the finish is applied before or after fitting, and what fixings are used. A quote that simply states "supply and fit trellis" without those details is not a like-for-like comparison with one that specifies them fully.

Custom garden trellis fitted by Haverhill Fencers is built at our Haverhill base and installed across Newmarket and the surrounding area. Call us to arrange a site visit and a clear, step-by-step quote.