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Let’s talk mold.

There’s mold lurking underneath

Let’s talk mold.

It’s quite the topic here in Costa Rica. Rain or shine there is mold lurking somewhere.

Fifteen years ago when I first started making canvas rugs I did not paint the back of the rug. It was raw cotton canvas.

New addition to combat mold.

After a few years, I decided to paint the underside of the rugs with a coat of house paint. The rugs are still flexible and have extra protection considering the problem of humidity, especially in lowland tropical rainforests!

Since canvas rugs are coated with several coats of polyurethane there has never been a problem with staining. I tell my clients to treat the canvas rugs as they would a hardwood floor, for example, put protective pads on furniture to prevent scratching the varnish.

In the kitchen, I like to use disinfectant. Sometimes I use Sani Pine but usually, it’s white vinegar. I have wood floors, so I sweep them and pass a damp mop to pick up dust.

Costa Rica has a dry season with six months of no rain, so it gets dusty here. Then we get six months of rain every day. Now we’re dealing with muddy shoes and muddy paws for those of us with furry friends.

Mopping a rug is so much easier than shampooing!


MOLD is the culprit when canvas rugs have a stain.

I visited a client in Dominical which has a lowland tropical weather system and saw a red vein running through the center of the canvas rug in their kitchen. I asked what is that stain? Since it was red, she answered, “oh that must be a stain from red wine!” Well, I have spilled plenty of red wine in my day and it never stained any of my rugs. And the vein shape looked strange.

I asked if we could lift the rug and there was a crack in their cement floor! This brought up moisture that caused the rug to mold underneath.  I tried to reseal the underside but without repairs on the floor itself, there is no solution for the mold.

In the end, I suggested taking up the rug because it was dangerous to have mold growing under it.

canvas floor cloth
wet and steamy jungle weather

New products help to combat moisture,

A canvas rug can’t cover up the problem and eventually, it will rot away.

I recently sold a rug to a young couple in my town Santa Barbara de Heredia. This is a higher altitude with 6 months of wet and 6 months of dry weather. Within weeks they reported some stains on the rug and were afraid of damaging the rug trying to scrub them out. I remembered the “red wine” incident and asked them to lift the rug to see what was going on underneath.

Sure enough, there was mold. Their concrete floor had been poured two months before we laid down the rug. I don’t know the building specifics about how this floor was built but moisture was coming through.

We pulled up the rug and first applied hydrogen peroxide, well known to eliminate mold. Then I scrubbed the bottom with diluted Clorox. Mold travels through 4 layers of paint and interacts with the varnish creating a stain.

New paint to coat the underside

I managed to sand the top, reapply paint and varnish to cover the largest spots.

I then asked my paint store if there was a special paint for the penetration of moisture and I bought a new paint that I will now use to paint under all of my rugs.

The client is treating the concrete floor to prevent moisture from coming up and we’re also putting a thin rubber mat under the rug as an extra precaution.

No type of rug can withstand moisture and mold.

Now I’m taking the extra step of using impermeable mold-resistant paint canvas rugs to have a better chance of protection!

If you have any questions about canvas rugs write to me at

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Love and design,


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