Before Anything Is Unpacked
Three checks, all of which are cheap now and expensive later.
The wall. For a wall-hung cabinet, establish what the wall is made of and whether the backing is present. Masonry takes appropriate anchors directly; timber or metal studs need noggins or a continuous backing plate, and if that was not installed before boarding, the installation stops here and becomes a construction problem.
The services. Check that the waste and supply positions match the cabinet as manufactured, particularly the drawer layout. If they do not, this is the moment to establish it, not after the cabinet is fixed.
The goods. Check the cabinet, top and basin against the order and inspect for transit damage before anything is unpacked beyond what is needed to see it. Damage reported after installation is much harder to resolve.
- Establish the wall construction and confirm backing is present
- Check the service positions against the actual cabinet
- Inspect for transit damage before installing
- Confirm the top and basin match the order
- Check the room is dry and finished enough to install into
Setting Out and Fixing
Everything references a level datum line, not the floor. Floors are rarely level and a cabinet set out from one will be too.
Mark the finished counter height on the wall, then work back down to the cabinet fixing line. For a wall-hung unit that line is the top of the mounting rail or bracket; for a floor-standing unit it tells you how much the plinth needs to be adjusted.
For a wall-hung cabinet, fix into the backing or the masonry with anchors rated for the loaded weight, which includes the top, the basin, the water in it and someone leaning on it. Check level in both directions before tightening fully, because a cabinet fixed slightly out will show as a tapering gap at the top and will make the doors sit unevenly.
For a floor-standing cabinet, level with adjustable feet or packers, and fix back to the wall to prevent it moving. Scribe the plinth to the floor if the fall is visible.
- Set a level datum line from finished floor level, not the floor itself
- Work back from the finished counter height to the fixing line
- Anchors rated for the loaded weight, not the empty cabinet
- Check level in both directions before final tightening
- Floor-standing: level on feet or packers, then fix back to the wall
Top, Basin and Plumbing
Dry-fit before anything is committed. Place the top without adhesive and check the fit against the wall along its full length. If there is a gap, decide now whether it is closed by a scribe, a filler or a sealant joint, because that decision changes how the top is fitted.
Fit the tap and the waste to the basin before the top goes down permanently, where the design allows. Working on a tap from inside a fitted cabinet is unnecessarily difficult, and it is the single most common reason a straightforward installation runs long.
Then connect the supplies and the waste, and test properly: fill the basin and release it, rather than just running the tap. A slow leak at a waste connection only shows under a full head of water, and it will be found later by the customer rather than now by the installer.
- Dry-fit the top and check the wall junction along its full length
- Fit tap and waste to the basin before final placement where possible
- Connect supplies and waste, then test under a full basin
- Check the trap position against the drawer boxes as fitted
- Confirm doors and drawers operate before proceeding
Sealing and Final Checks
Sealing is last, after testing, and it should be treated as a finish operation rather than an afterthought.
Clean and dry both surfaces, apply a continuous bead of a sanitary-grade silicone with fungicide, and tool it in one pass. A joint tooled repeatedly picks up debris and never looks right. Where a top has a formed or coved upstand, this joint may not be needed at all, which is one of the quiet advantages of that detail.
Then run the final checks: doors and drawers aligned and closing softly, hinge adjustment made rather than left, the top sitting flat with no rock, no visible gap at the wall, and the waste access panel fitted if there is one. Wipe down and leave the care instructions.
The last item matters more than it sounds. Most finish damage in the first year comes from cleaning products, and a two-line note prevents it.
- Test everything before any sealant is applied
- Clean and dry surfaces, one continuous bead, tooled in one pass
- Adjust hinges rather than leaving doors slightly out
- Fit the waste access panel where one is designed in
- Leave written care instructions with the customer
