Site records

Checking renovation work before anyone signs it off

Four procedures, written the way a site supervisor runs them: a 2 m straight edge laid on plaster, a hygrometer sealed to a screed for 72 hours, a nylon rod tapped across finished tiles, and a numbered register that carries every open item to a dated sign off.

Section drawing of a plastered wall checked with a straight edge next to a tile setting out grid and a floor build up of slab, membrane, insulation, screed and tile — The three checks that catch most renovation defects: wall flatness, tile setting out, floor build up.

01.What do the four renovation inspection procedures cover?

Four procedures cover the four handovers where renovation defects concentrate: plaster flatness measured under a 2 m straight edge, screed thickness and moisture measured before any finish goes down, tile lippage measured across each joint with a feeler gauge, and a written punch list that carries every open item to a dated sign off.

Each procedure page names the instrument, the reference length the instrument works over, the acceptance figure, and the wording that turns a failed reading into a priced repair. Read the procedure page the evening before the inspection. An inspection is a poor moment to start arguing about what the limit should have been.

01.

Checking plaster flatness

Straight edge method, deviation of 2 mm to 5 mm under a 2 m edge by following finish, raking light at 10 to 20 degrees, and 5 to 28 drying days before each decoration.

02.

Floor screed tolerances

Minimum thickness of 25 mm to 75 mm by construction type, drying at 1 mm per day, hygrometer limits of 65 to 75 percent RH by finish, and SR1 to SR3 flatness grades.

03.

Tiling quality checks

Lippage of 0.5 mm to 2 mm by joint width, grout joints of 2 mm to 10 mm, bed coverage of 80 to 100 percent, and movement joints at 3 m to 10 m centres.

04.

Running a renovation punch list

Room inspection route, twelve register fields, severity categories with 0, 7 and 28 day deadlines, and retention falling from 5 percent to zero across three gates.

02.Which acceptance figures get quoted at a renovation handover?

Eight figures account for most renovation handover disputes: plaster gaps of 3 mm to 5 mm under a 2 m edge, screed flatness of 5 mm under the same edge, screed moisture at 75 percent RH before ceramic tile, tile lippage of 1 mm on 3 mm to 6 mm joints, and adhesive coverage of 95 percent in wet areas.

Every figure in the table below is a working limit used on fit out jobs, and the contract specification overrides any line of the table where the two disagree. The straight edge length column matters as much as the limit column, because a 5 mm gap under a 2 m edge and a 5 mm gap under a 300 mm edge describe two different defects.

Table 1. Acceptance figures used at handover

Check	Instrument and method	Straight edge length (mm)	Working limit (mm, or percent where marked)	Procedure page
Plaster flatness, matt emulsion in a corridor	Largest feeler blade that enters the gap without force	2000	5	Plaster
Plaster flatness, satin or gloss paint	Largest feeler blade that enters the gap without force	2000	3	Plaster
Abrupt step at a bead, reveal or board joint	Feeler blade under a short edge held across the step	300	2	Plaster
Screed flatness under ceramic tile, grade SR2	Largest feeler blade that enters the gap without force	2000	5	Screed
Screed moisture before ceramic tile	Hygrometer box sealed to the surface for 72 hours	None	75 percent RH	Screed
Tile lippage, joints 3 mm to 6 mm wide	Feeler gauge under a short edge laid across the joint	300	1	Tiling
Adhesive bed coverage, wet areas and floors	Lift one tile and measure the contact area on the back	None	95 percent	Tiling
Perimeter movement joint where tiling meets a wall	Steel tape at five positions along the perimeter	None	6 to 10	Tiling

Working limits collected from fit out practice, not from a quoted standard clause. Confirm every value against the project specification before rejecting any work.

Kit for a handover walk

2 m aluminium straight edge, sighted against a known flat surface every 30 days
300 mm straight edge for local steps at beads, reveals and tile joints
Feeler gauge set covering 0.05 mm to 5 mm in 0.05 mm steps
Crack width gauge card reading 0.1 mm to 2 mm
Work lamp on a low stand, held within 300 mm of the surface for raking light
Nylon tipped tapping rod for hollow tiles and hollow render
Surface hygrometer boxes, one per 200 square metres of floor
Digital thermohygrometer reading to 0.1 degrees Celsius and 1 percent RH
Camera with a date stamp and numbered marker cards from 001 upward
Printed register with every room number already filled in

03.Why does every tolerance on this site carry a measuring method?

A tolerance without a measuring method cannot be enforced against a trade. A gap of 4 mm means nothing until the straight edge length is stated next to the gap, and a screed reading of 78 percent RH means nothing until the hygrometer sealing time and the room temperature appear beside the reading.

Every table on this site therefore prints the instrument, the reference length and the unit in the column heading. The about page lists the instruments, the reading resolution of each instrument, and the recording habits behind the four procedures.