Sanding wooden floors: a renovation project to be done by a professional, even if it represents costs

Houses that are several hundred years old still have their original floors made of real hardwood, nailed in the old-fashioned way, according to Emmanuel Cosgrove, general director of the organization Écohabitation.

Mr Cosgrove, however, estimates a lifespan of around 20 years for floors pre-finished in the factory, or nailed and varnished on site.

“The floor is durable, but the weak link is the finish you put on it,” Cosgrove said in an interview. “For a long time, you put varnish on it, but the varnish will eventually wear off and it will leave gray spots.”

The latter also categorically recommends oiled floors. “Because oil, unlike varnish, penetrates the surface of the wood, protects on the surface and in depth,” explains Mr. Cosgrove.

Lifetime warranty!

René Villeneuve, owner of Planchers Summum in Montreal for 40 years, has been doing oil finishing for 11 years.

“In our case, sandblasting is guaranteed for life with oil because it is always possible to repair without resanding,” explains Mr. Villeneuve, whom we met. You can’t do that with varnish.”

Bruno Rodriguez, owner of Planchers BR, expert in sanding and installing floors, also mentions that sanding hardwood floors can last more than 20 years.

“Durability depends on several factors, including regular maintenance and the level of traffic on the floor,” says Rodriguez.

What to know about sandblasting

Hardwood floors (including species such as oak, maple and cherry) are the most common for sanding, Rodriguez said.

“Prefinished floors can also be sanded,” Rodriguez says. “But they may require less frequent sanding because of their factory finish, which is often more durable.”

Sanding every 20 years should therefore be sufficient for prefinished floors. “However, durability also depends on wear and maintenance,” repeats Mr. Rodriguez.

Water drops and tolerance

But how do you know if your floor needs to be sanded?

A simple test is to place a few drops of water on the floor, according to Mr. Rodriguez. “If water is absorbed quickly, that indicates the wood is exposed and sanding may be necessary,” he explains. This is also the case if you have black stains on your floors, due to lack of varnish.”

The tolerance threshold is, however, the first thing to take into consideration, according to Mr. Villeneuve, of Planchers Summum. “Some people will not tolerate scratches and others will tolerate large spots of wear, where the floor has turned black because there is no more varnish,” relates Mr. Villeneuve.

Do not sand yourself

But if there’s one thing people shouldn’t do themselves, it’s sanding floors, Villeneuve said.

“The rental machines are not that easy to use, even just changing the sandpaper,” explains Mr. Villeneuve, who sometimes takes on clients who have done it themselves.

“Sandblasting requires a precise technique to avoid irregularities,” agrees Bruno Rodriguez. “Excessive pressure can cause irreparable damage to the floor.”

Costs

As for costs, Mr. Villeneuve gives the example of a 1,000-square-foot house (with 600 to 700 square feet of wood), at $4 per square foot. He estimates that the cost will range from $2,500 to $3,000 for sanding and finishing.

“If we want to add stain, it will be a little more,” he said, specifying that prices will vary from $3.50 to $6 per square foot. It depends on a lot of things, for example will the companies put a sealer and a coat?

Mr. Rodriguez mentions that the average price varies from $3 to $5 per square foot, including standard sanding and a basic finish.

Maintenance after sandblasting

Maintaining a varnished floor requires avoiding household detergents or oil-based soaps, Rodriguez says.

“Dish soap or vinegar can damage the finish,” Rodriguez warns. “For hardwood floors, it’s best to use a solvent-based cleaner.”