HENRY® 547 UniPro™ Universal Underlayment

Our best universal underlayment, for use as a patch, underlayment, or embossing leveler. HENRY 547 Universal Underlayment is used for preparing substrates to accept flooring. Its unique formula makes it extremely versatile for use with almost any substrate. Follow the flooring manufacturer’s specific installation recommendations HENRY 547 Universal Underlayment can also be mixed with HENRY 546 Feather Edge Additive and used as an embossing leveler over existing single-layer resilient flooring prior to the installation of new residential resilient flooring. HENRY 547 Universal Underlayment bonds to concrete, ceramic tile, quarry tile, and terrazzo (except metal terrazzo strips), wood and wood underlayments (wood should be suspended; not for stripwood floors), clean and abraded steel, stainless steel, brass and lead, primed poured-in-place gypsum subfloors, and radiant-heated subfloors where the surface temperature does not exceed 85°F (29°C).

[JayBobJayBob]

Thank you for these basics. Would’ve been nice to see you repair that original messed up floor. But the implication of your video is that I can use it to fill in that big wall gap in the floor.

[Insidiousotter]

Can I use this to level a bathroom floor that slopes 1/2" end to end?

[EdStaniszewski]

I have an old vinyl floor i thought i was going to remove. There are nails everywhere and old black mastic underneath. I removed a small area to see if i could remove. It is very difficult. So i am wondering if i can use the 547 to trough over the old vinyl and little bit of exposed mastic or tar paper? Would i need the 546 additive? You dont mention for some reason??

[mycats]

The instructions I was given on the mixing ratio was 2-1/2" cups powder to 1 part water. First time I'm hearing 3 cups. It would be way too thick with 3. I will say that this needs the 546 additive. I used water instead and it cracked, but the layer I did with additive was extremely solid.

[aubreyholman]

What's the difference between 547 and 549?

[dgregscottpublicvideos]

Per directions in this video and on the package, I mixed a 25 pound bag with a 3:1 ratio of powder to water by volume - about 2 1/4 units of water to about 6 1/2 units of powder. I used a paint mixing container to measure my water and powder, about 1 1/2 quarts. Converting to quarts - I used about 3 3/8 quarts of water to 9 3/4 quarts of powder. I stirred with a drill for three minutes and the mixture hardened in my bucket within seconds. Instead of fixing a low spot on my subfloor, I ended up with a 5-gallon bucket filled with 25 pounds of solid cement ready for a landfill.

I returned the empty powder bag, along with a bucket of useless hardened cement back to Home Depot and Home Depot exchanged it for another bag. This time, I used 4 containers X 1.5 quarts each = 6 quarts of water with a 25 pound bag. The mixture was about the consistency of pancake batter and lasted 15-20 minutes before hardening, as expected. But it did not fully dry for more than 24 hours after spreading it.

You need to update your mixing instructions on both the packaging and this video. You should also reimburse Home Depot for taking back my empty powder bag.