Blockwork & Brickwork Contractor in Cornwall

Substructure and foundation blockwork

Below ground the priorities are strength, durability and keeping water out. Trench blocks or dense concrete blocks are built off the footing in a mortar mix suited to below-ground exposure, cavities are filled or drained as the design requires, and the damp proof course is set at the correct height above finished external ground level. Drainage penetrations are formed with the required clearance and lintelling as the wall is built, not cut through later. Getting the substructure level and square is what makes every course above it straightforward.

Cavity walls, insulation and ties

A modern cavity wall is a system. Wall ties are specified for the cavity width, spaced to the design, embedded properly in both leaves and set with any drip sloping to the outer leaf. Insulation is either full fill or partial fill with a maintained clear cavity, fitted tight with no gaps at joints, joists and openings, and continued down to the required level. The cavity is kept clean as work proceeds, mortar droppings collecting on ties or insulation are the single most common cause of unexplained internal damp. Vertical damp proof courses and closers seal the cavity at reveals.

Facing brickwork and blockwork finishes

The outer leaf is what everybody sees for the next century. Setting out matters: courses worked out so openings, cills and heads land on a course, perpends kept plumb, gauge consistent, and bond maintained around corners and returns. Mortar is mixed consistently for colour and strength, and pointing is finished to a single profile: struck, bucket handle or recessed - across the whole elevation. Where we are matching into existing brickwork we take care over mortar colour and joint profile, because a badly matched patch is more obvious than the original defect was.

Structural openings, lintels and beams

Openings are where blockwork becomes structural engineering. Lintel type and length, bearing at each end, padstones under concentrated loads and steel beam sizes all come from the engineer's calculations. In new work the opening is built in; in existing structure the load is propped and needled, the beam installed, bearings built solid and the load transferred down through the structure to something capable of carrying it. Cavity trays and weeps go above every external opening. Building control inspects this work, which is exactly as it should be.

Retaining and boundary walls

A wall holding back ground is doing a different job from a wall holding up a roof. Retaining walls need a designed footing, reinforcement where the height and load require it, free-draining backfill and a land drain behind them so water pressure does not build up, and weep holes or a drainage outlet. Cornish sites, with their slopes and their rainfall, are unforgiving of walls built without those. Boundary and garden walls need proper footings below the frost line, movement joints in long runs, and copings that shed water rather than let it soak into the top of the wall.

Materials and mortar

Specification is chosen for duty and exposure:

• Dense concrete and trench blocks below ground and where load or durability demands it
• Aircrete and lightweight blocks where thermal performance and speed suit the design
• Facing bricks and blocks selected for exposure, and matched where extending existing work
• Mortar mixes matched to the unit, the exposure and the structural requirement
• Stainless wall ties, cavity closers, trays, weeps and damp proof courses to the design
• Lintels, padstones and steel beams to the structural engineer's schedule
• Bed reinforcement and movement joints where long runs or openings require them

Repairs, rebuilds and older solid walls

We rebuild cracked and bowed sections, replace failed lintels, take down and rebuild leaning walls, and cut out and replace spalled or frost-damaged brickwork. On older solid stone, granite and cob properties, detailing that suits modern cavity construction can trap moisture, so repairs are made in materials and mixes appropriate to the wall rather than in the strongest mortar available. Before any repair we look at why the wall failed: foundation movement, water, thermal movement or previous poor work - because repointing a crack whose cause is still active only hides it for a season.

New build shells, extensions and commercial work

On new build we take the shell from substructure through to wall plate, coordinated with our own groundworks and the carpentry that follows. Extensions add the complication of tying into existing walls, matching brickwork and building plumb against a house that is not. Developer work is about repeating a correct detail accurately across plots, and commercial and agricultural work brings blockwork to portal frames, heavier loads and larger openings. All of it from our base at Horningtops, across Cornwall and Devon as far as Exeter.