Asbestos, plasterboard, knotweed and tarmac: what rubble removal cannot simply take

Updated 6 November 2026 · By the Rubble Removal team

Short answer: Most brick, concrete, stone, soil and hardcore can be collected as ordinary rubble, but some materials need separate handling. Asbestos is hazardous waste and needs a specialist. Plasterboard must be kept apart from other waste. Soil containing Japanese knotweed must go to a permitted site. Older tarmac may contain coal tar and be classed as hazardous, and contaminated soil may need testing.

Asbestos, plasterboard, knotweed and tarmac: what rubble removal cannot simply take

Why some materials are treated differently

Rubble collection is cheap compared with other waste because clean, inert material can be crushed and recycled or sent to landfill at the lower rate of landfill tax. From April 2026 the lower rate in England and Northern Ireland is £8.65 per tonne, against £130.75 per tonne at the standard rate. A small amount of the wrong material mixed in can push a whole load out of the inert category, or make it hazardous waste that a normal site cannot accept.

For that reason, a good collector will ask what is in the pile, look at it before loading, and set aside anything that does not belong.

Quick reference

Material	Can it go with rubble?	What happens instead
Brick, block, concrete, stone, tiles	Yes	Crushed and recycled as aggregate
Clean soil and stones	Yes, best kept separate	Screened and reused or landfilled as inert
Plasterboard and gypsum plaster	No, kept separate	Sent to gypsum recycling or a dedicated landfill cell
Asbestos cement, tiles, textured coatings	No	Specialist removal and hazardous waste disposal
Soil with Japanese knotweed	No	Specialist removal to a permitted site
Old tarmac that may contain coal tar	Only if tested and clear	Tested, then disposed of as hazardous if positive
Soil with oil, fuel, ash or rubbish	No	Tested and sent to a suitable site
Timber, metal, plastic	Can be collected, kept separate	Sorted and recycled at a transfer station

Asbestos

Asbestos was widely used in UK buildings until it was banned in 1999. In rubble, it most often turns up as asbestos cement in old garage roofs, sheds, soffits, downpipes and flue pipes, and in floor tiles, textured coatings and boards. You cannot tell by looking whether a material contains asbestos, so if your building was built or altered before 2000 and you find sheet materials, old tiles or coatings in the pile, treat them with caution.

Do not break, cut or sand anything you suspect contains asbestos
Keep it separate from the rest of the rubble
Get a sample tested by an accredited laboratory if you are unsure
Use a specialist with the right permits to remove and dispose of it

Rubble that has been mixed with broken asbestos becomes hazardous waste as a whole, which is far more expensive to dispose of than either material on its own.

Plasterboard and gypsum

Gypsum-based materials, mainly plasterboard and some plaster, must not be landfilled with biodegradable waste because together they can produce toxic hydrogen sulphide gas. Small amounts of plaster stuck to bricks are not usually a problem, but sheets of plasterboard, offcuts and bags of gypsum plaster should be kept in their own pile. Many household recycling centres have a separate plasterboard container, sometimes with a charge.

Japanese knotweed and invasive plants

Soil and plant material containing Japanese knotweed is controlled waste. It must only be taken by a registered carrier to a site permitted to accept it, and it is an offence to plant or otherwise cause knotweed to grow in the wild. Rhizome fragments as small as a fingernail can regrow, so contaminated soil should never be mixed with clean spoil or reused elsewhere. If you see knotweed near where soil has been dug, mention it before booking.

Old tarmac and contaminated soil

Tarmac laid before the 1980s may contain coal tar, which is classed as hazardous waste because of the chemicals it contains. Driveway and path tarmac of uncertain age is often tested before disposal, and a simple spray test or laboratory analysis is used to check. Modern bitumen-bound tarmac without coal tar can usually be recycled.

Soil can also be contaminated by oil or fuel spills, old bonfire ash, buried rubbish or former industrial use. Contaminated soil may need laboratory testing before a disposal site will accept it. If you notice unusual smells, colours, oily sheens or buried debris when digging, keep that soil separate and say so.

What you can do

Tell the collector everything that is in the pile, including anything you are unsure about
Keep suspect materials separate and covered
Photograph anything unusual and send it with your enquiry
Do not hide problem materials inside bags of rubble, as disposal sites inspect loads

Being upfront means the job can be priced and planned correctly the first time, with no load rejected at the disposal site and no surprise costs afterwards. If in doubt, a photo is always better than a guess.