Three Quotes, a Factor of Four, and Nobody With a Rule Out
A 1979 semi in the Midlands, back bedroom, ceiling done in the fan-and-comb pattern that every plasterer of that decade could throw in about forty minutes. Four coats of magnolia since. The owner wanted it flat because a new pendant threw light sideways across it every evening and turned the swirls into a relief map. Three quotes came in over a fortnight. One was PVA and skim. One was scrape it back, bond it and skim. One was a new sheet of board over the lot. The highest was a little over four times the lowest, and not one of the three had put anything against the ceiling other than a hand.
Artex was a brand that turned into a noun. The generic article is a textured coating: a powder, gauged on site, laid on thick and then combed, stippled or dragged before it went off. It went onto ceilings from the sixties into the nineties and it is still sold. Two things about why it was used matter later. It was fast, and it hid everything — which means that under a great many of these ceilings is board that was scrimmed rather than properly jointed, with nail heads standing proud and joints that were never levelled, because nobody was ever going to see them.
So the ceiling has to be read before it can be priced, and reading it produces exactly two numbers. The first is a laboratory result on a sample of the coating. The second is the depth from the top of the peaks to the bottom of the troughs, measured rather than described. Every downstream decision — which primer, how many coats, whether the plasterer even opens a bag, whether there is a skip on the drive — falls out of those two. A quote arriving without both is a guess wearing a price.
What ends up between the joist and the paint
- Ceiling joists — set out on a regular module in a house of this age, and the only thing in the whole stack that a screw can usefully reach
- Original plasterboard — usually thin by current habit and jointed only enough to disappear under texture, which is why what is under the coating is rarely flat Ceiling Plasterboard (Gypsum Board) Sheet Calculator
- Textured coating — the layer you measure with a depth gauge and never buy: its profile decides the route, and its date decides whether anyone may touch it
- Bonding undercoat — the coat that fills the troughs and then covers the peaks, ruled off to a plane and keyed — this is where the material actually goes Gypsum Plaster Brown Coat Volume Calculator
- Finish skim — two or three millimetres of finish plaster that reports the plane beneath it faithfully and corrects none of it Gypsum Plaster Finish Coat Volume Calculator
The Date on the Tub, Not the Date on the House
Textured coatings are among the most common asbestos-containing materials still sitting in occupied homes, and a combed ceiling in a house of this vintage is precisely the material that historically carried chrysotile. The date people offer is almost always the wrong one. Manufacturers reduced and then removed asbestos from these products through the 1980s, but the legal line in the United Kingdom is the prohibition that took effect in 1999, so the only date that supports a decision without a sample is a coating demonstrably applied after 2000 — not a family's memory of the extension being done in 1986. Work on it sits under the Control of Asbestos Regulations 2012, with the Health and Safety Executive's Asbestos Essentials task sheets setting out the controlled methods for non-licensed work.
The North American reader has the same ceiling under a different name. A sprayed or troweled acoustic finish — the popcorn ceiling — is surfacing material, and OSHA's construction asbestos standard at 29 CFR 1926.1101 presumes surfacing material in buildings constructed no later than 1980 to contain asbestos until sampling says otherwise. How the sample is taken and where the boundary between licensed, notifiable and neither falls are the survey article's subject in this series, not this one's.
What belongs here is the part specific to this job, and it is counter-intuitive. Rank the three routes by how much they disturb the coating and the order is the reverse of the order people assume. Skimming over the top wets it and covers it, and disturbs nothing except where a fitting is taken down. Boarding under it drives several hundred screws through it, and each of those is a small drilling operation into a material of unknown composition — the HSE publishes task guidance for drilling into asbestos materials for exactly this reason. Scraping it off is removal, and it is the only one of the three that sets out to put the coating into the air. Where a sample comes back positive and the coating is sound, the two routes that leave it in place are the ones an asbestos management plan is written to encourage.
One prohibition applies regardless of what the laboratory says. Nobody sands a textured coating. If the result is positive that is obvious; if it is negative it is still a mineral-filled coating, and dry abrading it releases respirable crystalline silica, regulated in the United States under OSHA 29 CFR 1926.1153 and in the United Kingdom under COSHH. Every technique in this article is a wet one or a mechanical one, and the orbital sander stays in the van.
Measure the Profile Rather Than Naming the Pattern
The trade prices from the pattern name — swirl, stipple, broken leather, bark, comb — and that is where the factor of four in the opening comes from, because two ceilings given the same name can differ by five millimetres of depth. The measurement takes about four minutes. Lay a short steel rule flat across the peaks, then measure from the underside of the rule down to the bottom of a trough with a depth gauge or the tail of a vernier.
Take it in at least three places, chosen deliberately rather than conveniently. A plasterer working by hand loads the middle of the room and thins out towards the walls, and a patch made good after a leak is a different thickness again. Record the deepest reading and the typical one as two figures; their average describes no part of the ceiling.
The second measurement is the one almost nobody takes, and it is the one that turns a straightforward job into an argument at the end. Run a two-metre straightedge across the ceiling in both directions and note the biggest gap under it. Because the texture hid every joint, a ceiling of this era was frequently never levelled at all: a step at a butt joint, a bowed joist, a proud nail head. That deviation does not get absorbed by the texture depth. It adds to it, and it is the part a skim is guaranteed not to fix.
Those two figures, read against the table below, choose the route. Nothing in the table is a rule from a standard — the depth bands come from what a finish coat and an undercoat are each formulated to do, which is why the constraint column names the document rather than pretending the band itself is published somewhere.
| What you measure | What that makes the job | The constraint behind it |
|---|---|---|
| Texture largely flattened by paint, under about a millimetre | A skim, once the adhesion question in the next section is settled | A finish coat is laid at a nominal two to three millimetres and follows the plane it is given |
| One to three millimetres, reasonably even across the room | Nibs knocked off, then a skim carrying the fill as extra thickness | Finish plaster laid much beyond about six millimetres has stopped being a finish coat |
| Three to eight millimetres, or varying wildly between readings | An undercoat to bury the profile, ruled flat, then the skim over it | Every plastering system puts levelling in the undercoat: BS 8481, BS EN 13914-2, ASTM C842 |
| Deep comb or bark, with shoulders that undercut | Board under it — filling an undercut profile is not reliable at any price | Plaster keys mechanically into a profile it can reach; it bridges one it cannot |
| A straightedge gap larger than the texture depth itself | Battens packed to a line and boarded, whichever the texture route said | Neither a finish coat nor a single undercoat is a levelling operation over that range |
| Coating that flakes, chalks or moves under a scraper | Board under it, whatever the depth gauge read | Nothing applied on top can be better bonded than the layer it is applied to |
| Any of the above in a house not yet sampled | Nothing at all, yet | Control of Asbestos Regulations 2012; OSHA 29 CFR 1926.1101 |
PVA Is Suction Control, and Suction Is Not This Ceiling's Problem
This is the question the whole job turns on and the one most commonly answered wrongly, usually by somebody who has got away with it twice. Polyvinyl acetate emulsion is cheap, it is on every van, and it does one job genuinely well: it moderates how fast a thirsty background pulls water out of fresh plaster. On bare board, on old lime, on a dusty scratch coat, that rate is the whole difficulty, and PVA is the right answer. A painted textured ceiling has the opposite condition. It drinks nothing. Four coats of vinyl emulsion over a set coating leave a surface with no suction to control, and treating a low-suction background with a suction-control product solves a problem the ceiling does not have.
Two separate mechanisms are being confused. Adhesion to a smooth, sealed face is mechanical, and mechanical key is what PVA conspicuously does not supply — it dries to a smooth film on a smooth film. Worse, ordinary building-grade PVA is re-dispersible: the dried layer softens again when the water in the plaster reaches it. That is why the trade rule has always been two coats with the plaster going on while the second is still tacky, and why the ceiling that fails is the one where the second coat went on at four o'clock and the plasterer arrived the following morning to a hard, glossy film. It looks like a perfect base. It is a slip plane with a lifespan of about a heating season.
The product actually specified for this background is an aggregate-loaded acrylic primer that dries to a gritty film with something in it for the plaster to grip. British Gypsum publishes Thistle Bond-it for smooth, low-suction backgrounds in its Thistle literature and its Site Book, and Knauf's Betokontakt sits in the same position in its European range. Whichever bag of plaster you are buying, its manufacturer publishes a background-preparation table pairing background type with primer and undercoat. Read that table, for that plaster. The primer and the plaster are one system, and a cross-brand pairing puts the technical support with neither.
There is a test that settles the question in ten minutes and it costs nothing. Pick a corner nobody looks at, score a hand-sized square through the coating with a sharp knife, and try to lift it with a stiff scraper. If it parts from the substrate as a slab, or brings the board's paper face away with it, the failure plane is under the coating and no primer applied over the top of it changes that fact. Then, and only where asbestos has been ruled out, wet a second patch and leave it twenty minutes: a coating that softens, blisters or lifts is water-sensitive, and it is about to be wetted by a primer and then by a bucket of plaster.
Three backgrounds fail it more often than the rest: texture over a distemper or a soft, weakly bound emulsion, where the ceiling hangs on a layer with no strength of its own; texture on board that has been through a roof leak, where the paper face let go behind a surface that still looks intact; and texture repainted in a high-sheen vinyl silk, which offers neither suction nor key. In all three the honest answer is a new sheet of board, and pressing on because the primer is cheaper converts a day-and-a-half job into a ceiling that comes down twice.
Skimming Direct, and the Millimetres That Are Not on the Bag
Where the gauge reads under about three millimetres, the straightedge is close, and the scrape test held, the ceiling is skimmed. Before any primer goes on, take the proud nibs off — the edge of a trowel or a wide scraper worked flat along the ceiling, wet, never abrasive. Miss one and it stands above the finished plane afterwards, catching the same sideways light the owner was complaining about in the first place.
Then the arithmetic, which is where this differs from every other skim. Over a flat board a skim is a nominal two to three millimetres and the volume comes straight off the area. Over a texture it is that nominal thickness plus whatever the profile swallows, and the profile is not a percentage you add to the area — it is a depth, and depth multiplies through the whole ceiling. Two passes laid at nominal over a two-millimetre stipple is not a two-millimetre job, and the plasterer who ordered it as one runs out with a corner to go.
About the fill itself, this site will not publish a factor it cannot support. No standard gives the void fraction of a texture that was combed by hand in 1979, and inventing one would be worse than admitting it. The defensible way to settle it is empirical and takes an hour: prime and skim one measured square metre, weigh the bag before and after, and scale that to the ceiling. In a house with the same pattern through four rooms, that hour pays for itself several times on the order. Where the hour is not available, take somewhere between a third and a half of the measured peak-to-trough depth as the mean fill for a rounded stipple, more where a comb has left wide flat troughs, and buy at the top of the range rather than the bottom — the material has a short working life and the merchant shuts at four.
One last thing that catches people used to new board. Over a sealed background the water in the plaster has nowhere to go but into the room, so ventilate it, do not drive it with a heater, and expect the timing between passes to run later than instinct says. A skim trowelled hard while it is still fat sets with a soft, chalky face that the first coat of paint finds for you.
Put in the ceiling area, then set the coat thickness to the nominal skim plus the fill you measured rather than to the nominal alone — and note that the field stops at six millimetres, because a finish coat laid thicker than that is an undercoat that has not admitted it.
The total area to receive the finish coat.
The applied thickness of the finish coat.
Finish coat plaster volume
23.56 gal
The finish coat is thin, and its quantity is small relative to the coats beneath. What it is not is forgiving — it reveals whatever the brown coat left behind rather than correcting it.
- Equivalent volume
- 0.12 yd³
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Gypsum Plaster Finish Coat Volume Calculator: 23.56 gal — shown in imperial, US market. The link sets both, so the result they see is the one on your screen.
Estimated cost — your price
This site holds no price list for this material — local prices vary too much to publish honestly. Enter your supplier's price and the result is costed with it.
What this calculation does not cover
- A FINISH COAT IS A THICKNESS OF 2-3 MM AND A QUESTION OF FLATNESS, not a quantity to be stretched. Applying it thicker to bury a background that was never levelled is the commonest cause of a finish that crazes or delaminates, and no material figure prevents it.
- Set is time, not quantity. A bag mixed and not used inside its working time is waste regardless of the area it would have covered, so the order is governed by how much can be laid in one working period as much as by the wall.
- Says nothing about the background it is going on to. Finish plaster over new board, over a brown coat and over painted plaster are three different preparations with three different suction conditions.
- Excludes the scratch and brown coats, which together account for most of a rendered wall's material.
- Coverage varies markedly with the texture being achieved; a smooth trowelled finish and a heavy float finish consume different amounts of the same product.
- Does not include the first coat new plaster takes before it is decorated, a mist coat or a primer made for new plaster, nor the paint that goes over it.
When the Comb Is Too Deep for a Finish Coat
Past roughly three millimetres the answer stops being a fatter skim and becomes two coats: an undercoat that buries the profile and is ruled off to a plane, and the finish over it. This is not a preference. Levelling belongs to the undercoat in every plastering system there is — it is where BS 8481 and BS EN 13914-2 put it in Europe and where ASTM C842 puts it for interior gypsum plaster — and the finish coat's defining property is that it reports the surface beneath it rather than correcting it.
Which undercoat matters as much as how much. A browning-class undercoat is formulated for absorbent backgrounds and relies on suction it will not find here; the product for a low-suction face is a bonding-class one, of which British Gypsum's Thistle BondingCoat is the version most UK merchants stock. Its nominal applied thickness overhead is published, and it is lower than the figure for a wall, because a thick coat of wet undercoat on a ceiling is fighting gravity for the whole of its set. Take that number from the manufacturer's current literature rather than from memory, and if the arithmetic wants more than one nominal coat, that is two visits with a cure between them, not one heavy pass.
The thickness to order against is not the depth you measured. The undercoat has to fill the troughs and then cover the peaks, because a coat ruled off level with the peak line leaves those peaks as hard points that telegraph through the finish inside a season — a ghost of the original pattern, visible only in raking light, which is the exact complaint the work was meant to cure. So the ordering thickness is the peak-to-trough depth, plus a cover over the peaks, plus whatever the straightedge said the plane was out by. Half the material is going into a profile that was measured in millimetres and is bought in litres, and that is the step where quantities run away from people.
Whether to scrape first is a genuine decision rather than a formality. Softening and removing the coating roughly halves the undercoat quantity and hands you a background you can actually see. It also converts the job into removal, with everything that carries where a sample came back positive — and even where it came back negative it puts water into paper-faced board that will not thank you. If it is coming off, work a wide scraper flat and shallow, keep the blade off the paper, and stop the moment the face starts to fur. A gel remover sold specifically for textured coatings beats a wallpaper steamer here, because it keeps the arisings wet instead of turning them into steam and dust.
- Settle the sample result before any tool, wet or dry, touches the coating.
- Take the depth in three chosen places, and the plane with a two-metre straightedge in both directions.
- Score and lift a hand-sized patch to find out what the coating is actually bonded to.
- Scrape or soften only once you have decided the coating is coming off, keeping the blade clear of the paper face.
- Prime with the primer the plaster's own manufacturer pairs with this background, not with what is already on the van.
- Rule the undercoat off above the peak line, key it, and let it cure to the published interval rather than to the end of the working day.
The area is the ceiling; the thickness is the number this section builds — trough depth, plus cover over the peaks, plus the straightedge gap — which is why the answer here is usually two or three times what people expect from a ceiling they describe as slightly textured. The field stops at ten millimetres, which is roughly where one pass overhead stops being one pass: if your arithmetic asks for more, run it twice and add the two answers rather than pretending the ceiling takes it in a day.
The total area to receive the brown coat.
The applied thickness of the brown coat.
Brown coat plaster volume
49.87 gal
The brown coat is the coat that makes the wall flat and plumb, and it carries most of the thickness. It is where the material goes, and its cure is what governs when the finish can follow.
- Equivalent volume
- 0.25 yd³
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Gypsum Plaster Brown Coat Volume Calculator: 49.87 gal — shown in imperial, US market. The link sets both, so the result they see is the one on your screen.
Estimated cost — your price
This site holds no price list for this material — local prices vary too much to publish honestly. Enter your supplier's price and the result is costed with it.
What this calculation does not cover
- THE BROWN COAT IS THE LEVELLING COAT, so its thickness is set by how far out the background is rather than by a specification. A wall straight to within a few millimetres takes the nominal thickness; a wall out by 15 mm (0.59 in) over its height takes whatever it takes, and the average is the only figure that matters to the order.
- Material lost to the floor is real and is not a percentage. Plaster that falls off the hawk or the trowel on a scratch-and-brown job is gone, and on a rough background it is a substantial share of a bag.
- Suction governs how much stays on. An unprimed, highly absorbent background pulls water out of the mix and changes both the working time and the thickness that can be hung in one pass.
- Excludes the scratch coat below and the finish coat above, which have different thicknesses and different coverage rates.
- Does not allow for over-thickness where the substrate is out of plane, which on an uneven background can add substantially to the quantity.
- Cure time before the finish coat is a programme item, and rushing it is a recognised cause of finish-coat crazing.
Boarding Under It Instead
The third route deserves considering earlier than it usually is. Where the sample came back positive and the coating is sound, a new sheet of board leaves it in place and encapsulated, which is what a management plan asks for rather than something you get away with. Where the coating is deep, undercut or poorly bonded, boarding steps around a bond that could not have been guaranteed. And where the straightedge found real deviation, boarding onto battens packed to a laser line is the only one of the three routes that can genuinely straighten the ceiling instead of reproducing it in a smoother finish.
It is also a markedly easier job here than on the Victorian ceiling covered elsewhere in this series. The joists in a house of this age were set out on a regular module, the original board's own fixings mark those lines for anyone prepared to look, and the sheets were hung in one direction, so the first joist is found in minutes rather than in an hour of probing. The screw length sum is the same one — new board, plus the coating, plus the original board, plus the bite the fastener standard requires into the joist — and the lath-and-plaster article works that stack-up through in detail, so it is not repeated here.
Weight is the constraint that gets skipped. A second layer of board and its finish is permanent load added to joists sized for one layer, which have since acquired whatever the loft accumulated — the ground BS EN 1991-1-1 and ASCE/SEI 7 govern. A second limit is easier to check and just as binding: the board maker, and ASTM C840 in North America, publish a maximum framing centre for each board thickness in ceiling application, tighter overhead than on a wall. Check your measured centres against that table before choosing a thickness.
Counting sheets here is unlike counting them for an irregular old ceiling, and in a helpful direction: the layout can be planned, so the waste allowance is driven by the perimeter and by the fittings rather than by cutting every sheet to chase a joist somebody set out by eye. Count the fittings before ordering, because each one is a hole in a sheet — the rose, the alarm base, the extract grille, the hatch lining, and any downlights a previous owner added.
Take the sheet count off the measured ceiling area against the sheet size you can actually get up the stairs, with a waste allowance that reflects a layout you get to plan — the perimeter and the fittings, not the chase-the-joist waste an irregular ceiling forces.
SettingsSettings for this calculation
The standard allowance most suppliers and estimating guides assume for ordinary work.
The total area of the ceiling to be sheeted.
The coverage area of a single gypsum board sheet — a 1.2 × 2.4 m sheet is 2.88 m², a 4 × 8 ft sheet is 32 sq ft.
Extra material to allow for cut waste around fixtures, edges, and openings.
Ceiling sheets needed
8 sheets
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Ceiling Plasterboard (Gypsum Board) Sheet Calculator: 8 sheets — shown in imperial, US market. The link sets both, so the result they see is the one on your screen.
Estimated cost — your price
This site holds no price list for this material — local prices vary too much to publish honestly. Enter your supplier's price and the result is costed with it.
What this calculation does not cover
- Counts sheets without asking which board. Ordinary 1/2 in (12.5 mm) board on ceiling framing at 24 in (600 mm) centres is marginal, which is why the 5/8 in (15 mm) and sag-resistant grades exist, and a water-based texture or a load of blown insulation on top of the wrong one has it sagging between the joists inside a season. The sheet count is identical either way; the ceiling is not.
- Butt joints are why board length matters on a ceiling, and a count made of areas cannot see them. A ceiling is best hung with the longest board that will get into the room, because a butt joint has no tapered edge to bury the tape in and every one of them shows under light raking across the ceiling from a window — eight-foot and twelve-foot sheets can give the same number here and a visibly different finish.
- Area taken off a plan is not the surface of a raked ceiling. A vaulted or sloped ceiling holds more board than its footprint by the slope factor, and trays, coffers and bulkheads add returns that never appear on a plan at all.
The Finish That Is Not a Skim at All
Not every boarded ceiling gets skimmed. Across North America it is taped and coated as a matter of course, and plenty of UK work is finished the same way. Doing it over a ceiling that used to be textured carries one problem no other room has: the client's eye has spent twenty years on a ceiling with no visible joint anywhere, because the texture concealed every one of them. A jointed finish that would pass without comment on a wall reads as a defect overhead, and it reads worst under exactly the low sideways light that made the swirls objectionable in the first place. Which rung of the finish ladder to specify, and what each rung costs in coats and in scrutiny, is the taping article's subject — the point to carry here is that this ceiling wants a higher rung than the walls of the same room do.
That choice, not the area, is what moves the quantity. Two ceilings of identical size finished at different levels consume materially different amounts of compound, because the upper rung coats the entire face while the lower ones cover only bands over the joints and the fastener heads. So take the area from the sheet layout above, then pick the coverage rate for the level you actually wrote down. GA-214 defines what each level is and how much of the face it coats; the rate itself belongs to the compound, so take it from that manufacturer's data sheet rather than from the merchant's shelf-edge figure, which quotes whichever level flatters the tub. Order the finish before the boarding starts: discovering at the taping stage that the ceiling needs the top rung is a discovery about the programme as much as about the material.
Price the compound against the boarded area at the rate for the level of finish this ceiling actually needs, which on a room that has just lost its texture is usually one rung above whatever the specification says for the walls.
SettingsSettings for this calculation
The standard allowance most suppliers and estimating guides assume for ordinary work.
The total drywall surface area being taped and finished.
Compound scraped back into the pan, left to skin over, and sanded off the wall.
Joint compound needed
1 4.5 gal box
Textured ceilings, level-5 finishes, or heavily-taped small rooms (more seams per sq ft) use more compound than this flat-area estimate assumes.
- Area to finish (with waste)
- 473 sq ft
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Drywall Joint Compound Calculator: 1 4.5 gal box — shown in imperial, US market. The link sets both, so the result they see is the one on your screen.
Estimated cost — your price
This site holds no price list for this material — local prices vary too much to publish honestly. Enter your supplier's price and the result is costed with it.
What this calculation does not cover
- The pan-and-sanding loss is one percentage over the whole area, so it does not rise by itself for a room of many outside corners and butt joints, where more compound comes back off the wall; set it higher for a room like that.
- One coverage figure stands for the whole three-coat sequence, so embedding, fill and finish are never separated: a job stopped after the tape is bedded, or one given an extra pass over butt joints, will not track the number shown.
- Only the mud itself is counted — the paper or mesh tape bedded into that first coat, the beading on external angles and the fasteners buried underneath are all bought by length or by count, and a single area figure cannot produce either.
- Imperial answers round up to whole boxes while the metric answer is the bare mass required, so the two sides of the unit toggle are not the same figure in different clothes, and neither side deducts an opened box already standing in the van from a previous room.
- The metric figure is worked back from the published net weight of that same North American 4.5-gallon box rather than from the rated spread printed on a locally stocked tub, so a compound mixed to a different density or solids content will not land exactly on it.
The Cove, the Rose and Everything That Just Got Recessed
A ceiling of this period nearly always has a coved perimeter, and each of the three routes does something different to it. A skim closes onto the cove and needs the arris cut in cleanly. An undercoat plus a skim thickens the ceiling into the cove's top member and visibly narrows it, which in a low room is noticed without being identified. A new sheet of board buries it outright, so the cove comes off and a new run goes back — a separate length measured around the room and a separate day, and how that run is set out and jointed is the coving article's ground rather than this one's.
The same recess catches the services. Board plus finish drops the ceiling by something in the region of fifteen millimetres, and everything mounted in it is now that much proud of its hole: the loft hatch lining, the extract duct, any downlight cans and their fire hoods, and the mains-powered smoke alarm base whose position and interconnection are governed in the UK by BS 5839-6. The pendant drop needs slack a 1979 lighting circuit rarely has spare. None of this is difficult, and all of it is a second visit from a trade that has already been paid off if it is discovered on the day.
Then the handover. A plastered ceiling does not take full-strength emulsion straight off the trowel; it wants a mist coat while it is still curing out. A taped-and-coated one is a patchwork of porosities — paper face in one place, dried compound in another — and wants a primer sealer if the finish is not to flash a map of every joint back at the room. Either way the decorator's first coat is part of the specification, not something bought after the tower has gone.
The two measurements, then the material
The workspace opens on a twelve square metre bedroom ceiling in the finish-coat calculator, with the undercoat, the boarding and the jointing stacked beneath it. Change the area to your own room — but take the two readings in the first three lines before you touch any of the four, because they decide which of them you are actually using.
- Sample result, or a coating demonstrably applied after 2000 — The date the family remembers is not evidence. Until this line is closed, every other line in the list is theoretical.
- Peak-to-trough depth, in three chosen places — A steel rule across the peaks and a depth gauge into the trough. Record the deepest and the typical as two figures, never their average.
- Straightedge gap, both directions — Ceilings hidden under texture were often never levelled. This deviation adds to the texture depth rather than hiding inside it.
- Scrape test and, if cleared for asbestos, a wet patch — Finds out what the coating is bonded to and whether it is water-sensitive. A failure here sends the job to the boarding route regardless of depth.
- Primer chosen from the plaster maker's own background table — PVA controls suction on an absorbent background. This one has none. An aggregate-loaded primer is what the literature pairs with a sealed face.
- Cove, rose, alarm base and hatch lining decided before ordering — A skim narrows the cove, an undercoat narrows it more, and a new board buries it. Everything mounted in the ceiling ends up recessed.
Opens the calculators above on one screen with the dimensions from this article already filled in. Quantities only — this site publishes no price list, because local prices vary too much to publish honestly.