Use corrosion-resistant decking screws rather than standard wood screws. In the UK climate, standard zinc-plated screws will rust and can eventually snap under pressure as the deck moves with temperature changes. Look for screws with an exterior-grade coating, often green or brown, that are rated for outdoor use. For hardwood decking, pre-drill pilot holes first to prevent splitting. The screw should sit flush with or just slightly below the board surface without digging in too deep.
Screws, Nails, Adhesives and Building Chemicals
MacBlair stocks a comprehensive range of fixings, adhesives and building chemicals to cover everything from first fix to finishing. Screws for wood, drywall, decking and concrete sit alongside nails, nuts, bolts and wall plugs, so the right fastener for any substrate is always within reach. Plasterboard fixings, anchors, spring toggles and insulation fixings round out the mechanical side of things.
The adhesives and sealants range covers a lot of ground. Grab adhesives and silicone sealants handle most bonding and weatherproofing tasks, while expanding foams fill gaps around windows, doors and pipe penetrations. PVA, wood glues, contact adhesives, felt adhesives and floor adhesives all feature, along with anchoring resins for chemical fixings in masonry. For tiling jobs, tile adhesive and grout are available in their own dedicated section.
The chemicals range includes brick and patio cleaners, damp and waterproofing treatments, fuels, oils, and additives and dyes for concrete and mortar. Primers and lubricants are also stocked, covering surface prep and maintenance in one place. The category also holds practical site and storage items:
- Tapes, bungees, straps and rope for securing loads on site
- Chains, links and hooks for lifting and lashing applications
- Shelving, wardrobe rail and handrail brackets for internal fit-out work
Whether a job calls for a single box of screws or a full basket of site chemicals, MacBlair makes it simple to order online and collect or take delivery across Northern Ireland. Browse the sub-categories or search by product type to find what is needed.
Chemical and Adhesive FAQ's
Silicone sealant is a flexible, waterproof compound applied in a bead to seal joints and gaps, most commonly around baths, windows, worktops and sanitary ware. Expanding foam is a polyurethane-based material that expands and hardens to fill larger voids, such as gaps around window frames, pipe penetrations and door frames. The two products are often used together: foam fills the bulk of a large gap, and silicone is applied over the trimmed foam to provide a neat, weatherproof finish. Silicone will not stick to uncured foam, so always allow the foam to fully cure and trim it back before applying sealant on top.
Standard wall plugs are designed for solid masonry walls such as brick or concrete. They work by expanding inside a drilled hole when a screw is driven in, gripping the surrounding material. Plasterboard fixings are specifically made for hollow cavity walls where there is no solid material behind the board. They spread the load across the back face of the plasterboard once inserted. Using a standard wall plug in plasterboard will not hold properly and can pull through under load, so it is important to use the correct fixing type for the substrate.
PVA is a versatile bonding agent widely used in construction for priming surfaces, bonding lightweight materials and as an additive to cement mixes, but it is not suited to structural load-bearing joints on its own. For structural timber joints, use a purpose-made wood glue rated to at least D3 (water-resistant) for interior use, or D4 for exterior and damp conditions. Wood glues penetrate the timber fibres and form a strong internal bond, but for anything carrying significant load, mechanical fixings such as screws or bolts should be used alongside the adhesive for best results.
Drywall screws are the correct choice for fixing plasterboard to timber studwork. They have a bugle-shaped head that sits flush with the board surface without tearing the paper face, and a sharp point that drives easily into timber. The head should be driven just enough to dimple the surface slightly without breaking through the paper, as this weakens the holding strength. For walls, space screws approximately 300mm apart along each stud. For ceilings, reduce the spacing to around 200mm. Avoid using ordinary wood screws as they can tear the board face and do not countersink cleanly.