Kitchen Worktops - Wooden Installation

Slotted brackets
The wooden kitchen worktops are fixed down using slotted stretcher brackets only, (with slots uppermost!). The cross grain slots in the brackets, together with round headed screws, will accommodate the natural movement of the timber whilst holding the kitchen worktops down.
Use typically 2 brackets per end panel on 560-570mm deep base units at 500-600mm centres.
Deeper units will need more brackets pro-rota.


Wooden Kitchen worktops Bracket fixing
Fix the brackets to the base unit side panels only. (The top rails are not strong enough). Use 4 x 15mm RHd screws.

b) Units with top panels
On units that have a full or partial top panel, fix the brackets directly under the panel, having first drilled 15mm minimum access holes through the top to line up with the cross grain slots in the brackets.
Use 4 x 35 - 38mm Rttd screws to fix through the bracket and unit top into the timber.

Note:
These top panels must be drilled or cut out over at least 50% of the area to allow the underside of the timber worktops to breath and stay in balance with the upper surface.

c) Wooden Kitchen Worktops above kitchen appliances
Where the wooden kitchen worktops span appliances alone, or are unsupported into the corner, cut and fix timber wall rails to support the tops and attach the slotted brackets.

Tops that span two appliances side-by-side must be supported:
- either by a mid panel fixed between them.
- or by a solid timber front rail at least 40mm high and fixed across the span.

d) Onto masonary features
Do not fix wooden kitchen worktops directly onto masonary. Fit them over timber spacers 6 - 10mm thick, which are themselves on a Damp Proof Membrane (DPM). This prevents the transmission of moisture and provides an airspace under the top.

Appliance moisture barrier
Fix moisture barrier to protect the underside of the wooden kitchen worktops from heat and steam produced by built-under washing machines, dishwashers and microwaves.
The barrier comes in sheet form.
Staple or tack it to the underside of the tap from just behind the capillary groove extending to the back edge and sideways to overlap the adjacent units.

Sealing corner joints
Make sure any end grain has been sealed before assembling the joints.
Apply a light bead of clear low modulus silicone sealer along one side of the joint, just below the top surfaces and edges.

Align the two sides with biscuits before clamping up firmly with worktops bolts. Wipe off the surplus sealer.

Fixing wooden kitchen worktops
For Belfast sinks, just before the wooden kitchen worktops is put in place, run a bead of low modulus clear silicone along the outer half of the sink rim, at the sides and the rear, to form the primary seal to the worktops.

Move the tops into place. Use thin pieces of board as temporary packing to position them with 4 - 5mm expansion gaps between the edges and ends of the tops and the walls.

Pilot-drill at the centre of the cross grain slot:

- use Æ4 x 20mm Rtd screws when fixing directly to the worktops
- use Æ4 x 35-38mm screws when fixing through brackets and units with tops.

Tighten the screws fully, then just loosen them by turning back a quarter turn. This stops the screws binding against the brackets and allows the wood to 'move'.

Cupped tops
If wooden kitchen worktops are cupped, due to moisture differences on site between the opposite surfaces of the wood, it should be fixed down through the rear brackets first. Then gently and gradually, using clamps and battens, pull it down at the front before fixing it there with screws.
Allow time for the timber surfaces to equalise and flatten, otherwise the timber may be split.

Undermounted sink installation
a). The narrow strip of wooden kitchen worktops between double sinks must be

reinforced with a timber rail. Fit the rail with a method that allows the worktops to 'move' while it is being supported.

b). Run a medium sized bead of clear low modulus silicone around the rim of the sink, offer it up and fix it under the cutout with sink clips.

c). On undermounted and Belfast type sinks, with 27 & 40mm worktops only, add more silicone as required and form a smooth cone between the inside of the sink and the underside of the worktops all round the opening.

Lay-on appliance and sink installation
Fit lay-on appliances according to the manufacturer's instructions using the sealing materials provided by them.
With lay-on sinks, if no seal is supplied, use a generous of clear low modulus silicone.
If the walls are to be tiled, place a temporary spacer on the worktops to form a 3-4mm gap across the bottom of the tiles. After tiling and grouting seal the gap with low modulus silicone to stop moisture and allow timber movement.