One Building, Two Volumes
A structure carries two volumes at once. The first is the solid it occupies while standing — bank volume, the figure your drawings, your tape and your survey produce. The second is what that same material occupies after it has been broken, tumbled down a chute and dropped into a container. Haulage, container hire, gate fees, wheel-wash time and traffic management are all bought against the second number. Almost every estimate is built from the first. The ratio joining them is swell, and it usually carries the widest error band of anything on the sheet.
Set that ratio too low and the shortfall does not announce itself until the third day, when the yard holds rubble it cannot shift and the machine sits idle waiting on an exchange that is crawling through town traffic. Loads bought late arrive on somebody else's timetable, and the standing time they cause is charged to you rather than to the haulier. Three unplanned lorries on a tight urban plot can cost more in lost machine hours than they do in haulage.
Over-ordering is the quieter failure. Part-filled containers occupy the same footprint, block the same crane oversail, and are collected under the same minimum charges as full ones, but they take away air. On a job with one loading position, every wasted exchange is a delay to the next drop as well. Working from a defensible conversion in both directions is what keeps the container schedule honest against the demolition programme.
Fixing the Solid Number Before Anything Moves
Take the bank volume off element by element rather than as a single building envelope. Slab thickness and reinforcement class, wall thickness by storey, screed and finish depths, roof build-up, blockwork versus solid brick, and the frame itself all convert differently later, so they have to survive into the takeoff as separate quantities. A lumped figure in cubic metres of building is useless once you need to know how much of it is metal going to a different gate at a different rate.
Deductions carry more weight here than in a build takeoff, because you are removing what was never there. Window and door openings, service risers, lift shafts, ducts, stair voids and cavity widths all subtract real solid. On a heavily glazed commercial frontage the openings can strip a meaningful share off the masonry quantity, and carrying them as solid inflates every downstream number in proportion.
Below-ground work is where solid volume hides. Ground-bearing slabs sit on hardcore that was never drawn, pad footings turn out deeper than the record drawings show, and old basements appear as backfilled voids. A trial hole or two before the estimate closes is cheaper than discovering an extra half-metre of mass concrete once the breaker is on site. Where an engineering survey is required before demolition begins — as it is under regulations such as OSHA 29 CFR 1926 Subpart T, Demolition — use that visit to confirm construction thicknesses rather than only structural condition.
Bulking Belongs to the Method, Not Just the Material
Two crews taking down identical bays of the same building will produce different loose volumes. A hydraulic breaker leaving lumps the size of a wheelbarrow gives a far bulkier heap than a pulveriser or crusher jaw working the same concrete down to fist-sized pieces. Method statement, attachment choice and how much secondary breaking you are prepared to do sit upstream of the swell figure, which means the estimate cannot be closed before the demolition method is chosen.
Typical assumptions to start from, all of which want confirming against your own loads: broken concrete and masonry commonly land somewhere near one and a half times their solid volume; brick rubble a little less; mixed hardcore between the two. Light framing timber, ductwork and roof sheeting are in a different world entirely, expanding several times over because they trap air rather than pack. Plasterboard behaves well while it is still in sheets and badly the moment it is snapped.
Measure once and you own the number. Pick a bay whose solid volume you have taken off precisely, count the loads it actually generates, and back-calculate the factor for that structure and that attachment. Two or three of those records across different building types are worth more than any published table, because they carry your plant, your operators and your loading discipline inside them.
Converting Solid to Loose
Once the solid quantities and the demolition method are settled, the conversion becomes a single arithmetic step that everything else hangs from: container count, exchange frequency, stockpile area, haul cycles and gate cost all descend from it. Doing it per stream rather than for the building as a whole keeps the error contained, since one badly judged factor on the timber then cannot contaminate the concrete figure.
Run the conversion twice — once on your working assumption and once on the pessimistic end of the range — and look at the gap in lorry numbers rather than the gap in cubic metres. That difference is the real exposure, and it tells you whether the job needs a firm container schedule or a call-off arrangement with slack in it.
The takeoff is finished and the method is chosen, so this is the point where solid volume has to become the loose volume everything downstream is bought against.
The intact, in-place volume of the masonry or concrete before demolition.
The type of masonry/concrete being demolished — different materials bulk by different amounts.
Estimated bulked (swelled) volume
26 yd³
These are typical demolition-estimating swell factors, not a universal engineering constant — actual bulking varies with the demolition method (mechanical breaking vs. explosive vs. hand demolition) and resulting debris piece size. Use a higher factor for finely broken debris and confirm against your hauler/estimator's experience on similar material.
- Swell factor used
- 1.3 x
They open the calculator with your figures already in it
Demolition Bulk Volume Swell Calculator: 26 yd³ — 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 in-place volume from a length x height x thickness take-off is the structure alone, and the container receives everything attached to it. Plaster and render, screed, cavity insulation, timber lintels and bearers built into masonry, tile and its bedding — none of that contributed to the solid volume entered, all of it leaves in the same load, and on a finished internal wall it is a substantial share of what goes out.
- The swell factors are for material that breaks into loose pieces, and reinforced concrete does not. The bar holds broken slabs together, so the debris stands in tangled sections occupying far more space than 1.3 times its solid volume until the reinforcement is cut out. A reinforced slab, a ring beam or an RC frame needs the bar handled as its own operation, and the volume on the ground before that happens bears no relation to this figure.
Lump Size and the Fill You Actually Achieve
Loose volume and container capacity are not measured the same way, and treating them as interchangeable is a second error stacked on the first. A container is rated by its geometric cube; a heap of demolition arisings inside it bridges, arches over the corners and refuses to level. Coarse rubble with a wide lump size can leave a good share of that rated cube as unusable air unless someone works the load down with the bucket.
Oversize pieces cause a separate problem at the gate. Anything that overhangs the rim has to come out before the sheet goes on, and a load turned away for protrusion is a wasted cycle plus a re-handle in the yard. Cutting slab and beam sections to a size the box can swallow is slower at the point of breaking and faster across the day.
Fines behave in the opposite direction and catch people out on weight. Crushed material and screed dust pack tight, fill the voids and put a container over its weight ceiling while it still looks half empty. The same box that carries a full load of light strip-out will be closed at a third of its depth when it is taking clean concrete fines.
Each Stream Swells on Its Own Terms
Source separation changes the arithmetic before it changes the recycling figures. Metals, clean concrete, timber, plasterboard and general mixed waste each have their own bulking behaviour, their own density and usually their own destination, so they are separate calculations from the start. A mixed container ends up governed by whatever fraction swells worst — a handful of ductwork runs and stud partitions will dictate the cube of a load that is nominally masonry.
Soft strip generates the volume nobody budgets for. Carpet, ceiling tiles, insulation, furniture and partition linings weigh almost nothing and consume containers at a rate that looks absurd next to their tonnage. Programming soft strip as its own phase with its own container sizes, rather than folding it into the structural allowance, is what stops the first fortnight eating the whole waste budget.
Hazardous streams sit outside the swell calculation altogether. Asbestos-containing materials are sized by their packaging and their consignment route, under whichever regime applies — the United States works to the National Emission Standards for Hazardous Air Pollutants asbestos provisions at 40 CFR Part 61 Subpart M, other jurisdictions to their own national asbestos regulations. Those loads are counted in wrapped units, and they must be gone before the structure comes down.
Sizing the Box Against Both Ceilings
Every container has two limits and the job hits one of them first. Bulky, light material fills the cube while the axle load is still comfortable; dense material — concrete, brick, tile, screed — reaches the weight ceiling with the box visibly part-filled. Choosing a size means knowing which ceiling binds for that stream, and it flips between phases of the same demolition.
Weight limits are set by road traffic law and vary by jurisdiction, so gross vehicle and axle limits are the haulier's constraint to confirm rather than yours to assume. What lands on you is the consequence: an overloaded skip that cannot leave the plot, a vehicle turned back at the weighbridge, and a re-handle that occupies the loading position for half a shift. Small containers for heavy arisings and large ones for strip-out is the pattern most sites converge on, and it is worth setting deliberately rather than by accident.
With loose volume per stream in hand, the remaining decision is which container size takes it without hitting a weight ceiling first.
The estimated loose volume of debris you need to haul away.
How solidly the debris packs into the container — irregular debris leaves air gaps.
Recommended dumpster size
20 yd³
Standard sizes and availability vary by hauler and region — confirm exact dimensions and weight limits with your specific waste hauler, since some materials (e.g. concrete, dirt, roofing) have separate weight-based limits regardless of the container's volume.
- Required capacity accounting for packing
- 20 yd³
They open the calculator with your figures already in it
Dumpster/Skip Container Size Selector: 20 yd³ — shown in imperial, US market. The link sets both, so the result they see is the one on your screen.
What this calculation does not cover
- The smallest box that holds the debris is not always the box the site can take. A 40-yard roll-off is around 22 ft (6.5 m) long and wants roughly 60 ft (18 m) of straight, level approach for the truck to winch it off, plus about 23 ft (7 m) of overhead clear of wires and branches; a 10 or a 15 will sit in a driveway where a 40 cannot even turn around. Check the drop before ordering the size the volume asked for.
- Volume here means level-full. Roll-offs are hauled with nothing above the top rail, because the load has to be sheeted and it has to be legal down the road, so a container heaped over the sides is either re-worked on site before it leaves or left behind. The packing efficiency you entered describes air trapped between the pieces, not the freeboard the driver needs above them.
- One box means one mixed load, and mixed is the expensive way to get rid of material. Clean concrete, clean fill, scrap metal and cardboard each go out at their own rate, sometimes at no charge or a rebate, and dropping any of them into the general box carries them all at the mixed construction-and-demolition rate. A diversion target usually means a second, smaller container rather than a single larger one.
Stockpile Footprint and the Haul Cycle
Loose volume lands on the ground before it lands in a box, and on a constrained site the stockpile is the binding constraint. Divide the loose volume you expect between exchanges by a realistic heap height — not the theoretical angle of repose, but what the machine can safely build and reach over — and you have the footprint the arisings need. Where that footprint will not fit, the container schedule has to tighten regardless of what the haulage cost says.
Machine positioning follows from the same number. One excavator loading, breaking and feeding a crusher cannot do all three when the stockpile has swelled past its swing radius. Plan the loading position, the exchange path and the wheel-wash so that a lorry arriving does not stop the demolition face, because standing time on the machine is the cost that compounds.
Sequencing keeps the two volumes in step. Soft strip and hazardous removal come first and generate high-cube, low-weight loads; structural demolition follows with the reverse profile; crushing and muck-away close it out. Safeguards during that sequence sit under standards such as NFPA 241, Standard for Safeguarding Construction, Alteration, and Demolition Operations, ANSI/ASSP A10.6, Safety Requirements for Demolition Operations, and BS 6187, Code of practice for full and partial demolition.
Exchange frequency is a fleet question underneath: load, run, tip and return is one cycle, and how many lorries that cycle needs is what decides whether the face keeps working or stands watching the gate.
Distance from load point to dump.
Average speed carrying a load.
Average speed running empty.
Time under the loader.
Spotting, tipping and turning at the dump.
Loose volume carried per trip.
Trucks in the fleet.
Real productive minutes in an hour.
Hourly production
217 yd³/hr
Match factor below 1 — the loader is standing idle waiting for trucks. Adding a truck will increase production.
- Cycle time per truck, free-flowing
- 14.5 min
- Loaded travel
- 6 min
- Return travel
- 4 min
- Match factor
- 0.83 ×
- Trips per truck per hour, free-flowing
- 4.14 trips
- Loader ceiling at 100% efficiency
- 315 yd³/hr
- Trucks for a balanced fleet
- 4.83 trucks
They open the calculator with your figures already in it
Truck Haul Cycle Time Calculator: 217 yd³/hr — shown in imperial, US market. The link sets both, so the result they see is the one on your screen.
Add the equipment this sizes
This result is a specification — 217 yd³/hr — not a quantity. Put the thing it sizes into your project: how many, what you call it, and your supplier’s price.
What this calculation does not cover
- Assumes a steady haul road and constant speeds. Grades, single-lane sections and a shared road with other traffic all degrade this in practice.
- Payload is loose volume. Converting from bank measure requires the swell factor for the material, which changes the trip count.
- Does not model the dump-end constraint. A single spreader or a tight tip can throttle the fleet just as the loader can.
Where the Ratio Runs Backwards
Material that stays on site reverses direction. Concrete crushed for re-use as capping or piling mat goes from loose back toward compacted, and the compacted volume is less than the loose volume it came from. Three states are in play across the job — solid in the structure, loose in the heap, compacted in the ground — and mixing up which one a quantity is expressed in is the classic way a fill schedule ends up short.
On-site crushing is the strongest lever available on lorry count, because material re-used inside the hoarding never becomes a haulage movement at all. Whether you can run a crusher, and under what noise, dust and permitting conditions, is determined by local environmental regulation and the site permission, so confirm it before it appears as a saving in the estimate.
Do not assume crushed arisings substitute for imported fill one for one. Grading, fines content and contamination all decide whether the product meets the specification for its intended layer, and material that fails the spec has to leave anyway — after you have paid to process it.
Material that never leaves the hoarding travels through all three states in one movement, so run bank, loose and recompacted together rather than converting once and hoping the capping layer works out.
The undisturbed, in-situ soil volume.
How much the soil expands once excavated and loosened, as a positive percentage.
How much smaller the soil ends up once recompacted, as a negative percentage.
Loose (haul) volume
163 yd³
Swell and shrinkage factors vary significantly by soil type and moisture content — use site-specific values from a geotechnical report or local hauling experience where available, rather than generic averages.
- Bank (in-situ) volume
- 130.75 yd³
- Compacted (recompacted) volume
- 117.68 yd³
They open the calculator with your figures already in it
Soil Swell & Shrinkage Haul Volume Calculator: 163 yd³ — 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 swell and shrinkage percentages are figures you supply, not properties this page derives. Moisture content, fines content, how the material is dug and the compactive effort actually applied all move the real factors, and the same soil at a different moisture will not behave like the number you typed. Take the factors from the site investigation or measured local experience, not from a general table.
- This is a volume conversion, not a haulage calculation. It does not size trucks, count loads, or apply payload limits — wet or dense spoil often reaches a lorry's weight limit before it fills the body, and heap, tailgate profile and further bulking during loading all sit between this loose figure and a load count.
- The compacted figure is not a compaction specification. It assumes the placed fill achieves exactly the shrinkage percentage entered, and says nothing about the density the fill must be tested to, layer thickness, the plant used, or material rejected and reworked. It does not replace field density testing.
- One bank volume with one pair of factors. A mixed excavation — topsoil over clay over rock, or a trench through made ground — has different swell and shrinkage per stratum, and running the whole quantity at a single figure misstates both the haul and the fill. Topsoil stripping and unsuitable or contaminated material that leaves site instead of returning to fill are outside the model entirely.
- The loose volume describes material immediately after excavation. A stockpile consolidates under its own weight and with rain, so a survey of a pile that has stood for weeks comes back below this figure. Nothing here addresses waste classification, tipping, or duty-of-care disposal requirements for spoil going off site.
Reconciling Tickets Against the Assumption
Weighbridge tickets come back in mass while the estimate was built in volume, which makes them the cleanest audit you will get. Convert the tonnage back through a loose density for that stream and compare it against the cube you predicted; a consistent gap in one direction tells you the swell factor needs correcting for that building type before the next job, not that the haulier is wrong.
Documentation runs alongside the arithmetic. Waste transfer or consignment paperwork, and the waste classification codes for construction and demolition arisings, are set by the regime in force — the duty-of-care provisions of the Environmental Protection Act 1990 in England and Wales, state and federal requirements elsewhere. Where diversion is being reported for certification, the counting rules belong to the scheme, such as the construction and demolition waste management credit in LEED, or the recovery targets for non-hazardous construction and demolition waste set under the EU Waste Framework Directive 2008/98/EC.
Close every job by writing the measured factor into a log against the structure type, the attachment used and the lump size achieved. That log is the only thing that turns swell from a guess into a quantity, and it is what stops the same three surplus lorries appearing on the next demolition as well.
A density per stream is the missing term between what the weighbridge printed and what you predicted, and it has to go in before anyone decides whether the gap belongs to the factor or to the haulier.
The estimated debris volume — switch the unit to match your skip or container ticket.
The material's density — mixed construction & demolition debris commonly runs 300-800 lb/yd³ (180-475 kg/m³).
Estimated debris weight
6 tons
Debris density varies enormously with material mix (loose wood/insulation vs. concrete/masonry can differ by 5-10x) — use a density figure specific to your actual debris composition, ideally confirmed against a recent weight ticket for similar material, rather than a generic average.
They open the calculator with your figures already in it
Demolition Debris Weight-to-Volume Conversion Calculator: 6 tons — 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 total tonnage is not a number of loads, and loads are what you pay for. A container fills by volume or by weight, whichever arrives first: concrete and rubble weigh a truck out at a fraction of the container's rated volume, while light mixed debris cubes out long before the axle limit is anywhere near. Dividing this tonnage by a container's volume rating undercounts loads on heavy material every time.
- Density is a wet-weight property. An open container of gypsum, timber and insulation standing through a wet week gains weight without gaining volume, and the scale at the gate charges whatever is on the truck that day. A density taken from a dry load, or from a summer weight ticket, runs well under a winter one for exactly the same debris.
- A figure off a weight ticket is an as-loaded density, with the way that load was placed already baked into it. The same debris tipped loose from a chute, packed down by a grab, or hand-stacked into the container differs by around a third — so a density borrowed from a job that handled the material differently carries that difference across even when the material mix matches perfectly.
Before the first breaker starts
Five things worth pinning down while the structure is still standing, because every one of them changes the loose volume you have to move.
- Element-by-element solid volume — Slab, walls, frame, roof and below-ground kept separate — a single building figure cannot be converted per stream.
- Opening and void deductions — Glazing, risers, shafts and cavities removed from the masonry quantity before any swell factor is applied.
- Demolition method and attachment — Breaker, pulveriser or jaw decides lump size, and lump size decides bulking more than the material does.
- Trial hole confirmation of buried construction — Hardcore depth, footing size and any backfilled basement, checked against record drawings rather than trusted.
- Stream list with destinations — Metals, clean concrete, timber, plasterboard, mixed and hazardous each carry their own factor and their own gate.
- Stockpile footprint and loading position — Loose volume between exchanges divided by a workable heap height, checked against the machine's swing radius.
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.