Asbestos floor tiles: remove, cover or leave?

Which floors are suspect

Asbestos was added to many resilient flooring products for strength and heat resistance. In an older house, be cautious with:

• Vinyl and asphalt floor tiles, especially the 9 inch by 9 inch size, though 12 inch tiles were made too
• Sheet vinyl with a felt-like backing
• The black adhesive under tiles, sometimes called cutback mastic
• Levelling compounds beneath old floors

Age and appearance are only a guide. Several layers of flooring are common in older kitchens and basements, and a newer floor may hide an older one. Only laboratory analysis of a sample confirms whether a product contains asbestos.

How risky are they?

Floor tiles are a non-friable material. The asbestos is bound into a solid matrix and is not released by walking on the floor. Tiles in good condition, left alone, are low risk.

The risk appears when the tile is broken up and turned to dust:

• Sanding or grinding
• Dry scraping
• Using power tools to cut or drill
• Breaking tiles into pieces to lift them
• Sanding off the adhesive underneath

Grinding old adhesive off a concrete floor is one of the most common ways homeowners contaminate a house without realising.

Three options

Leave it

If the floor is intact and you are not renovating, leaving it is reasonable. Keep a note of it with your house records.

Cover it

New flooring can often be laid over sound old tiles: floating vinyl plank, laminate, carpet or a new subfloor. Do not sand the old surface to prepare it, and avoid fixing methods that drill through the tile. Remember that the asbestos is still there for whoever renovates next.

Remove it

Removal is the right choice when tiles are loose, broken or crumbling, when the floor level cannot rise, or when the renovation involves the subfloor.

How removal is done

In Ontario the work is classified under Regulation 278/05 according to the method. Lifting intact tiles with hand tools, kept wet, falls into a lower category than breaking, grinding or sanding them, which needs more precautions. In practice a careful removal involves:

1. Testing the tile and the adhesive
2. Clearing the room and isolating it, with heating and cooling vents sealed
3. Wetting the tiles and lifting them whole where possible
4. Dealing with the adhesive without dry sanding or grinding
5. Sealing all waste in labelled containers for disposal at a permitted site
6. HEPA vacuuming and wet wiping the room

If tiles have already been broken up

Stop work. Keep people out, shut off the furnace fan and do not sweep or use a household vacuum. Have the material tested and the area cleaned professionally.

Before you renovate a kitchen or basement

Have suspect flooring tested first, including any layers beneath. It is a small cost compared with the renovation, and it tells your contractor what precautions are needed. Contractors are bound by the regulation even where a homeowner is not.

Questions to settle before any flooring work

• How many layers are there? Lift a floor register or look at a doorway threshold. Old kitchens often have three or four floors stacked up, and each one is a separate material to test.
• What is underneath? Tiles on concrete and tiles on a wooden subfloor are removed differently. On wood, taking up the underlay with the tiles attached can avoid breaking them.
• Is the adhesive affected? The black mastic is tested separately from the tile. A clean tile result does not clear the glue.
• Who is doing the work? A flooring installer is bound by the regulation even in an owner-occupied house, and many will not start until the floor has been tested.
• Where will the waste go? Ask before work starts, and ask for the disposal paperwork afterwards.

Getting these answered at the planning stage costs little. Discovering them halfway through a kitchen renovation, with the room open and dust in the air, costs a great deal.

More: asbestos removal and abatement.