Laminated engineered timber posts
Laminated posts are built up from several thinner timber sections glued face to face under pressure, which can even out natural defects like knots across the section and produce a straighter, more dimensionally stable post than a single sawn piece of the same size.
Because the lamination process distributes any given defect across a smaller proportion of the overall section, a laminated post is generally less likely to fail suddenly at a single knot or grain irregularity than solid sawn timber.
The adhesive bond line itself becomes a potential weak point if it's exposed to sustained moisture without an appropriate exterior-rated glue, so laminated posts intended for outdoor use need adhesives specifically rated for damp exposure rather than interior-grade bonding.
Slotted versus morticed concrete posts
Slotted concrete posts have a continuous groove cast into two or four faces so panels slide down into the slot from above, which makes them fast to erect but means every panel in a run has to come out to replace one in the middle.
Morticed concrete posts have discrete rectangular pockets for arris rail ends instead, matching closeboard or panel construction where individual boards or panels can be replaced without disturbing the rest of the run.
The choice is largely dictated by the fencing system being used — panel fencing wants slotted posts, boarded fencing wants morticed — rather than being a free preference at quote stage.
Consent needed to connect drainage across a boundary
Running a new drainage connection across a neighbouring property's land, sometimes done alongside boundary works, needs the neighbour's consent and possibly a formal easement, not just a friendly verbal understanding.
Water companies can also require notice for new connections joining an existing public sewer, separate from any neighbour agreement about crossing their land.
Where fencing work uncovers or affects a drainage connection crossing the boundary, it's worth pausing to confirm what rights actually exist before proceeding.
Made ground from Victorian development
Much of the Victorian terraced housing across north London sits on plots that were levelled, infilled or built over earlier brickfields, clay pits and market gardens, leaving inconsistent fill rather than natural strata close to the surface.
A trial dig on these plots can turn up broken brick, ash, clinker or timber offcuts within the first spade's depth, none of which gives a post anything solid to bear on.
Where fill depth is unpredictable across a single run, post depths sometimes need to vary hole to hole rather than following one fixed spec for the whole boundary.
Setting out a line over a sloping plot
On a slope, a string line pulled level between two posts of equal height will sit above the ground at one end and below it at the other, so setting out has to work from a boning rod or a laser level rather than the string alone.
The usual method is to fix the top and bottom posts first, establish the actual fall between them, then decide bay by bay whether intermediate posts step down in even drops or follow the ground continuously.
Getting this decision agreed before any post is concreted matters, because changing from a stepped to a raked layout partway along a run after posts are set means starting again.
Keeping mortice depth consistent across a run of timber posts
Hand-cut mortices in timber posts can vary slightly in depth from post to post if they're cut freehand rather than to a fixed jig or depth stop, which then shows up as a rail sitting at a slightly different height at each junction.
A simple depth stop clamped to the chisel or drill bit, checked against the first mortice cut, keeps every subsequent one consistent without needing to measure each one individually from scratch.
Checking a sample rail against several mortices before committing to cutting the whole run confirms the depth is right before the error, if there is one, has been repeated across every post.
Maintenance intervals by material
Untreated or lightly treated softwood fencing generally needs a re-stain or re-oil every one to two years to keep its protective coating intact, while a well-detailed treated softwood fence left to weather naturally can go much longer between any active maintenance.
Composite and uPVC fencing need little more than an occasional wash down, since the material itself doesn't need a protective coating, though fixings and any timber sub-frame beneath it still age on their own separate schedule.
Metal railings and gates need their finish checked periodically for scratches or corrosion starting points, since a small breach in galvanising or powder coating left untreated will spread under the coating rather than staying contained.
Fencing above a basement lightwell or retaining structure
Where a boundary fence sits directly above a basement lightwell, sunken patio, or retaining wall with a significant drop on one side, the fence effectively doubles as a safety barrier and needs a height and gap specification suited to that fall risk rather than a standard garden boundary spec.
Post fixings in this situation often need to tie into the retaining structure itself rather than a simple ground-set post, which is a different engineering detail to a standard concrete-in post.
This is worth identifying clearly at survey stage, since treating it as a routine fence replacement without accounting for the drop below is a genuine safety oversight.
Closeboard and feather-edge construction
Closeboard fencing is built from overlapping feather-edge boards nailed vertically to horizontal arris rails, each board tapered so the thick edge overlaps the thin edge of its neighbour and sheds water outward.
That overlap is what gives closeboard its strength and privacy compared with a pre-made panel — there's no single failure point, so a split board can be replaced individually without dismantling the run.
The trade-off is labour: it's built on site board by board rather than lifted into place, so it costs more in time than a lap panel of the same length.
Tangential shrinkage and cupping
Wood shrinks more in the direction that runs tangentially to the growth rings than along the grain's length, and boards cut close to the outer edge of a log (flat-sawn) show this most, curling into a dish shape known as cupping as they dry.
A board with growth rings running roughly parallel to its face is far more prone to cupping than one cut through the centre of the log, where rings run closer to perpendicular to the face.
Fixing boards with two nails or screws per bearer rather than one resists cupping better, since a single central fixing lets the edges lift and curl relatively freely.
Corner plots and unusual exposure
A corner plot often loses the shelter of a neighbouring garden on one side, leaving a boundary that faces open street or open ground the way an interior garden fence never does.
That side of the plot is worth treating like a rural exposed boundary for post spacing and panel choice even though the rest of the garden is a normal suburban size.
It is also usually the run most visible to passers-by, so the practical answer is often a slightly heavier specification rather than a cheaper standard one to avoid repeat failures on the most conspicuous boundary.
Conservation area material rules
Inside a conservation area, the council can restrict fence height, colour and material even within otherwise-permitted development limits, usually through an Article 4 direction that removes some of the usual PD rights.
The common ask is close-boarded or picket timber in a natural or traditionally painted finish rather than modern composite or bright stains, particularly on frontages visible from the street.
For a listed building itself, or land within its curtilage, listed building consent can apply even to a garden fence, so it's worth a call to the conservation officer before committing to a spec.
Recommended inspection intervals for gate hardware
Checking hinge fixings, latch alignment and post plumb roughly twice a year, typically before and after the worst of winter weather, catches most developing faults while they're still a simple adjustment rather than a full repair.
A gate in heavy daily use, such as a bin store or communal alley gate, benefits from more frequent checks than a garden gate opened only occasionally.
Tree roots and Tree Preservation Orders
Mature trees close to a boundary do two things to a fence: their roots can heave a post out of true over several years, and if the tree is protected by a Tree Preservation Order or sits in a conservation area, digging within its root protection area needs care and sometimes council sign-off.
Where roots are already present we'll usually hand-dig around them rather than auger through, and set the post slightly off the direct line if that avoids cutting a structural root.
It's worth checking with the local authority's tree officer before any excavation near a TPO tree, since unauthorised root damage carries the same penalties as felling the tree itself.
Checking a post is plumb in two planes
A post checked with a spirit level on only one face can still be leaning across the run even though it looks vertical along it, so plumb needs confirming on two adjacent faces at right angles before concrete goes in.
This matters most on corner and gate posts, where a lean invisible from the main run direction becomes obvious the moment a gate is hung and doesn't swing true.
Rechecking plumb again just before the concrete starts to go off catches any post nudged out of position while backfilling or bracing, since that's a common point for a post to drift slightly unnoticed.
Checking screw and bolt length matches the timber section
A fixing that's too short doesn't engage enough timber to hold under load, while one that's too long can punch through the far face of a rail or post, both of which are easy mistakes when reaching for whatever's in the tool bag rather than checking the actual section thickness first.
As a rough guide, a screw fixing generally wants to penetrate the receiving timber to a meaningful multiple of its own diameter to hold securely, which is worth checking against the actual post or rail dimensions being used on a given job rather than assumed from habit.
Where a through-bolt is used instead of a screw, matching the bolt length to the combined thickness of both pieces plus washer and nut avoids either an unsightly protruding stub or a bolt that can't be tightened properly.
Composite fencing construction and expansion gaps
Composite fencing boards are a wood-fibre and polymer blend, usually clipped or screwed onto an aluminium or timber sub-frame rather than nailed directly, which avoids splitting the board and allows for its different movement characteristics.
Composite expands and contracts with temperature more than timber does, so boards are fitted with a small expansion gap at each end and between courses rather than butted tight, and a run installed without those gaps can bow or buckle in hot weather.
The sub-frame itself is usually still timber or aluminium posts rather than composite throughout, since composite isn't generally used as a structural post material.
Strainer posts and wire tensioning loads
A strainer, or straining post, anchors the end of a tensioned wire or mesh run and needs to resist a sustained pulling load along the line of the fence, which is a materially different stress to the mostly lateral wind load an intermediate post experiences.
Strainer posts are typically set deeper, in a larger concrete footing, or braced with a diagonal strut back to a second post, specifically to resist this sustained pull rather than an occasional gust.
Under-specifying a strainer post relative to the wire tension applied is a common cause of an entire fence run gradually leaning inward from one end, since the strainer post itself moves rather than the wire actually loosening.
Fencing alongside a shared access driveway
A driveway shared by two or more properties usually carries a right of way that limits how close a new fence can come to the actual running surface, regardless of who legally owns the land beneath it.
Width needs checking against the widest vehicle that regularly uses the shared drive, not just a car, since delivery vans and refuse vehicles are a common reason an otherwise reasonable-looking fence line turns out too tight.
Gates across a shared driveway need agreement from all parties with a right of way over it, and usually a means of access — a code, a key, or simply leaving it unlocked — for everyone who needs to use the route.
Step riser heights on a raised deck
Steps down from a raised deck work best with consistent riser heights throughout the flight, since an irregular step height is a common trip hazard, particularly where the top or bottom step differs slightly from the others.
Building regulations guidance for steps in a domestic setting generally favours risers in the range of roughly 150-170mm with adequate going (tread depth), though garden steps have more flexibility than an internal staircase.
Where a deck sits at a height that doesn't divide evenly into consistent risers, it's better to adjust the deck height slightly at the design stage than to build one oddly-sized step to make up the difference.
Key-alike locking across multiple gates
Where a property has several gates, key-alike cylinders let one key operate all of them instead of carrying a separate key for each, which is a straightforward upgrade at the point locks are being replaced anyway.
This needs cylinders sourced as a matched set from the outset rather than retrofitted individually afterwards.
Victorian terraces with rear alley access
Many Victorian and Edwardian terraces back onto a shared rear alley or 'twitten' rather than opening onto a private access road, and boundary fencing along that line is often a mix of ownership — some panels the householder's, some historically shared with the alley itself.
Alley gates onto these routes need to open inward or be set back, since a gate swinging out over a shared right of way can obstruct neighbours and bin collection.
Where the alley is council-adopted, replacing a boundary fence that fronts it can also need a look at any local byelaws on gate height and lockable access before ordering materials.
