For years Luan was used due to the fact that is was a solid plywood with no voids in the veneers. Were as "most" fir or pine plywood has voids and the premise was that a point heeled shoe on a sheet flooring would pop a hole when stepping on said void. From what I recall most linoleum was only warrantied installed over luan. The luan was more of a substrate than an underlayment however as it really did nothing other than back up the sheet flooring. Not sure if it is still recommended or not however.

"a point heeled shoe on a sheet flooring would pop a hole when stepping on said void"

Ah.. Interesting. That certainly makes sense.

"Were as "most" fir or pine plywood has voids"

That was the same thing my BF said. So maybe the issue is that Luan is no longer made without voids?

Anyone else have advice on this??

The underlayment will be grade stamped.

Read the Armstrong specifications for the type of underlayment required for the warranty to be valid.

Lauan Plywood

Quarter-inch lauan plywood is a popular choice as an underlayment among remodelers. It has a solid track record and is readily available. All resilient floor manufacturers allow lauan plywood under at least some resilient floor applications and some manufacturers recommend it as an underlayment for all applications. Check with your manufacturer before using lauan plywood.

There are two types of lauan: Type 1, with an exterior glue and Type 2 with a water-resistant glue. Only Type 1, which is more resistant to delamination, should be installed under resilient flooring. The “type” is stamped on the very edge of the panel, usually on the 4-foot edge. Three face-grades are available – BB, CC and OVL(overlay). BB is the highest grade and should be used whenever possible.

APA’s installation guidelines for 1/4-inch plywood should be followed when installing lauan plywood, but installers BEWARE: Lauan is made under a wall-panel specification of the International Hardwood Products Association (IHPA). No manufacturing specifications support its use or gauge its performance as an underlayment.

Wood Underlayments

Thanks, I have actually read the Armstrong Underlayment guide and they do allow a Type 1 lauan, and my contractor DOES use Type 1 lauan so that is not a question there. I am just wondering what the cons are for lauan, since all over the internet it is bashed, but in the real world, it is what most flooring installers seem to use. Frankly I would prefer to use the Halex underlayment.

Armstrong Underlayment guide and they do allow a Type 1 lauan ...so that is not a question there.

What do you mean? This is the exact question you asked.

Frankly I would prefer to use the Halex underlayment.

Why didn't you say that in the first place? This is the first time you mentioned Halex. Well go to their web site - and find the Halex product that meets the Armstrong specifications.

I’m not sure why my own preference matters. My question has nothing to do with that.

"What do you mean? This is the exact question you asked."

No, I never asked about what Armstrong allows. Armstrong allows a Type 1 Lauan, but then qualifies that with a big "but..it can present problems.....".

Maybe I need to clarify my question. Why do most of the flooring contractors still use a Lauan underlayment today, when it appears to be routinely bashed all over the internet?

Better safe than sorry with your flooring investment. Go with the Halex or Matrixx underlaymen. The only substrate type underlayment I’ve ever had a problem with one time with a Luan underlayment, long story but just know it’s the one and only time I’ve had an issue and it was with Luan. Also the Halex and Matrixx will do better with water events.

“Resists swelling and no delamination with extended water exposure. Passes the APA 2-hour boil test.”

https://www.traxxcorp.com/products/matrixx-underlayment/

"to keep themselves and their families fed, they have to use the cheapest of the cheap just to win a job"

I don't believe that at all. There are PLENTY of people out there willing to pay for a good job - and I'm one of them. But I'm not naive either. I have no intention of being ripped off again - I've had more than my share of it. Frankly, I think a flooring installer would improve their business if they stopped using crap materials and only offered a quality job with quality materials. Personally, I believe the issue is that there is SO much work and SO few competent tradesmen, it's just a greed issue.

I’m so sorry peopeople are ggetting ripripped off we did to we paid litle over $15,000.00 to have a porch and deck put on our home by ( a contractor) that turned out to be a (CON MAN) we were told by family member he was very good and worked on some million dollar homes our Deck is falling apart and the porch is rottening away!!! and my husbands Brother is the one that recomaned him to us he was so smart (Acting) like he was going to give us A Amazing job and wait he did is rip us off we tried to make him fix it and found out he was Not Bonded and Didnt even have A Contractors Licenses!!! Just A Con Artist that lived in South Congree SC Im just saying check out who you Trust To Do Anything!!! Dont take Anyone At Their Word And Get Everything In Writing Before You Hand Over Cash!!! 🥲🙏🏽

Dam, why do people who feel the need to bash people type such unreadable diatribes. Makes it dam near impossible to accept their story as the truth.