hardwoodfloorTV Hardwood Installer
It is currently Sat Oct 25, 2014 9:52 pm

All times are UTC - 5 hours




Post new topic Reply to topic  [ 17 posts ]  Go to page 1, 2  Next
Author Message
 Post subject: Why doesn't T-molding reach the sub-floor?
PostPosted: Mon May 23, 2011 12:25 pm 
Offline
New User

Joined: Mon May 23, 2011 10:28 am
Posts: 6
I have experienced numerous problems with the T-molding that I have purchased for my floating engineered hardwood floors: defective staining, splits in the ends of the molding, variation in width of molding sold for the same purpose,... This thread begins by addressing one such problem: the base of the T-molding is too short to reach the sub-floor.

I have finished with installation of 15 mm thick Kahrs engineered click-and-lock flooring. What remains is installation of the various transition strips. From the supplier of the Kahrs flooring strips, I ordered T-molding designed for the 15 mm thick flooring. I received T-molding that has an acceptable width and staining but the base of the T-molding (the vertical part of the "T") is only 12.5 mm tall. It won't reach to the sub-floor. I checked to make sure that I received the correct product. It was labeled with a UPC/barcode indicating that this T-molding was indeed designed for 14/15 mm Kahrs flooring.

One flooring contractor I discussed this with suggested that perhaps the T-molding was designed to be installed in a metal track. If so, then why didn't the flooring supplier mention such a track and why didn't they offer such a track on their website?

On another website, one installer noted that T-molding was frequently too short to reach the floor. To solve this problem he used shims. This is what I am now doing: gluing a 1/8" strip of wood to the base of the T-molding. Why was the T-molding designed to have a base of less than 15 mm?


Top
 Profile  
 
Find Professionals

 Post subject: Re: Why doesn't T-molding reach the sub-floor?
PostPosted: Mon May 23, 2011 1:39 pm 
Offline
Worthy Contributor

Joined: Sun Jun 27, 2010 8:28 pm
Posts: 447
Location: Minneapolis, Minnesota
This is pretty common. We always do just what you are doing and that is to put a thin strip for the tt-molding to rest on and to nail to.

_________________
Rhodes Hardwood Flooring
Minneapolis, St. Paul, MN
http://www.HardwoodFlooringMinneapolis.com


Top
 Profile  
 
 Post subject: Re: Why doesn't T-molding reach the sub-floor?
PostPosted: Mon May 23, 2011 3:12 pm 
Offline
New User

Joined: Mon May 23, 2011 10:28 am
Posts: 6
RhodesHardwood wrote:
This is pretty common. We always do just what you are doing and that is to put a thin strip for the tt-molding to rest on and to nail to.


Thanks for the reply. I phoned Kahrs and the support person there said that they intentionally cut short the base of the T-molding. Kahrs suggests that the construction adhesive should fill in the 3 mm gap.

If this is the case, my only remaining question is what happens if someone steps on the T-molding? Will the construction adhesive support the weight or will the T-molding be pressed down below the top of the floor and be subject to stresses that may crack an arm off of the molding?


Top
 Profile  
 
 Post subject: Re: Why doesn't T-molding reach the sub-floor?
PostPosted: Mon May 23, 2011 8:12 pm 
Offline
Valued Contributor

Joined: Mon Mar 14, 2011 4:36 pm
Posts: 652
"Will the construction adhesive support the weight or will the T-molding be pressed down below the top of the floor and be subject to stresses that may crack an arm off of the molding?"


only if its Kirstie Allie...


Top
 Profile  
 
 Post subject: Re: Why doesn't T-molding reach the sub-floor?
PostPosted: Mon May 23, 2011 8:51 pm 
Offline
Prized Contributor
User avatar

Joined: Sun May 24, 2009 7:48 pm
Posts: 1802
Location: Las Vegas
Bompata wrote:
I phoned Kahrs and the support person there said that they intentionally cut short the base of the T-molding. Kahrs suggests that the construction adhesive should fill in the 3 mm gap.


As said, it's common. But I would say it's common so the manufacturer can cross reference that same specie t- moulding for different product thicknesses.

The problem with filling the gap with adhesive...... One of the functions of a t-moulding is to allow proper expansion. Your not going to maintain proper expansion trying to fill the void of the leg. The adhesive just fills the expansion space.

I do like Rhodes says, and fir up the leg with a strip.

_________________
Howard Chorpash
Frazier Mountain Hardwood
http://www.lasvegaswoodflooring.com


Top
 Profile  
 
 Post subject: Re: Why doesn't T-molding reach the sub-floor?
PostPosted: Mon May 23, 2011 10:06 pm 
Offline
New User

Joined: Mon May 23, 2011 10:28 am
Posts: 6
Floorologist wrote:
Bompata wrote:
I phoned Kahrs and the support person there said that they intentionally cut short the base of the T-molding. Kahrs suggests that the construction adhesive should fill in the 3 mm gap.


As said, it's common. But I would say it's common so the manufacturer can cross reference that same specie t- moulding for different product thicknesses.

The problem with filling the gap with adhesive...... One of the functions of a t-moulding is to allow proper expansion. Your not going to maintain proper expansion trying to fill the void of the leg. The adhesive just fills the expansion space.

I do like Rhodes says, and fir up the leg with a strip.



Thank you all for your prompt and informative replies.

If you fill up the gap with a shim then the layer of adhesive must be pretty thin. Is that right? A quarter inch diameter bead?


Top
 Profile  
 
 Post subject: Re: Why doesn't T-molding reach the sub-floor?
PostPosted: Mon May 23, 2011 10:26 pm 
Offline
Prized Contributor
User avatar

Joined: Sun May 24, 2009 7:48 pm
Posts: 1802
Location: Las Vegas
Bompata wrote:
quote] If you fill up the gap with a shim then the layer of adhesive must be pretty thin. Is that right? A quarter inch diameter bead?


I run a bead on the subfloor, and a bead on the leg. I may take some heat on this...but I shoot 23 ga. wire to hold it secure also, ( I don't believe 23ga. will alter movement, and they're not noticable).

If I'm transitioning to tile....I tape off the tile, and fill the tile side of the "T", solid with clear 100% silicone. This also camoflauges the variation at the tile.

Over a wood subfloor...I avoid topnailing the leg with a larger gauge, ( don't like topnails, unless covered by base, etc.)

_________________
Howard Chorpash
Frazier Mountain Hardwood
http://www.lasvegaswoodflooring.com


Top
 Profile  
 
 Post subject: Re: Why doesn't T-molding reach the sub-floor?
PostPosted: Tue May 24, 2011 8:35 am 
Offline
New User

Joined: Mon May 23, 2011 10:28 am
Posts: 6
I thought I would give it a try with the approach recommended by Kahrs. I applied to the gypcrete sub-floor a very thick (1/2 inch) bead of Liquid Nails "Heavy Duty Interior and Exterior Construction Adhesive". I then put the T-molding (without any shim) in place and weighted it down on each end with some surplus tiles. Twenty hours later I pushed on the T-molding and found that it moved with minor pressure. When I lifted up the T-molding (again, this took minimal force) I found that the Liquid Nails was still very maleable and friable like caulk.

So that didn't work.

Now I am testing another sample with a shim glued to the base of the "T" and only a quarter inch bead of Liquid Nails. I will report the results in 24 hours. But I suspect I will find that I am using the wrong construction adhesive. Any other suggestions in addition to those offered by Floorologist above (i.e. apply a bead on the leg of the T as well as a bead on the subfloor)?

Thanks, Bob


Top
 Profile  
 
 Post subject: Re: Why doesn't T-molding reach the sub-floor?
PostPosted: Tue May 24, 2011 9:14 am 
Offline
Prized Contributor

Joined: Sat May 02, 2009 3:45 pm
Posts: 2877
Location: Tucson AZ
Over concrete you may want to use a better grade adhesive that is moisture cured like PL Premium. I install the transition areas so I and glue the back side of the T to the tiles edge. Better support, just make sure you weight it down good or they will not set all the way.

_________________
Stephen Perrera
Top Floor Installation Co.
Tucson, Arizona
Floor Repairs and Installation in Tucson, Az
http://www.tucsonazflooring.com


Top
 Profile  
 
 Post subject: Re: Why doesn't T-molding reach the sub-floor?
PostPosted: Tue May 24, 2011 9:36 am 
Offline
New User

Joined: Mon May 23, 2011 10:28 am
Posts: 6
Thanks. I am googling for "best construction adhesive" and I see a variety of recommendations:

"PL 200 or PL 400";
"Loctite PL Premium Polyurethane Constructition Adhesive";
"Bostik's Best" (moisture-cured urethane);
"Sika Construction Adhesive" (polyurethane);
Henkel PL Premium Polyurthane;
Gorilla glue

Does anyone know of a systematic review of such adhesives?

Will any of them hold wood to concrete (or gypcrete in my case) long-term?


Top
 Profile  
 
 Post subject: Re: Why doesn't T-molding reach the sub-floor?
PostPosted: Tue May 24, 2011 10:01 am 
Offline
New User

Joined: Mon May 23, 2011 10:28 am
Posts: 6
I just learned that Loctite/LePage/Henkel are now the same company. That is why "PL Premium" moisture-cured polyurethane construction adhesive is marketed under all 3 names. The Loctite brand is available at Home Despot.

But will it keep wood bonded to concrete (or gypcrete) for several years?


Top
 Profile  
 
 Post subject: Re: Why doesn't T-molding reach the sub-floor?
PostPosted: Tue May 24, 2011 6:19 pm 
Offline
Prized Contributor

Joined: Sat May 02, 2009 3:45 pm
Posts: 2877
Location: Tucson AZ
Yes the Pl Premium will bond but gypcrete is notoriously dusty. Make sure you work it into the surface and also the transition strip.

_________________
Stephen Perrera
Top Floor Installation Co.
Tucson, Arizona
Floor Repairs and Installation in Tucson, Az
http://www.tucsonazflooring.com


Top
 Profile  
 
 Post subject: Re: Why doesn't T-molding reach the sub-floor?
PostPosted: Tue May 24, 2011 8:37 pm 
Offline
Prized Contributor
User avatar

Joined: Sun May 24, 2009 7:48 pm
Posts: 1802
Location: Las Vegas
For bonding....it helps to scarify the concrete with open coat sandpaper. Then vacume, wipe down clean with damp rag, let dry.

_________________
Howard Chorpash
Frazier Mountain Hardwood
http://www.lasvegaswoodflooring.com


Top
 Profile  
 
 Post subject: Re: Why doesn't T-molding reach the sub-floor?
PostPosted: Tue May 24, 2011 10:02 pm 
Offline
Prized Contributor

Joined: Sat May 02, 2009 3:45 pm
Posts: 2877
Location: Tucson AZ
Good point about the sand paper Howard. Especially if there is Lord knows what on the surface. Using a damp rag to clean up the dust is also excellent. But the PL Premium is a moisture cure urethane so if the surface is slightly damp it sticks better. It cannot however be wet, just damp. I used to stick carpet tackstrip down on concrete and ceramic tile like that, works wonderful and fast.

_________________
Stephen Perrera
Top Floor Installation Co.
Tucson, Arizona
Floor Repairs and Installation in Tucson, Az
http://www.tucsonazflooring.com


Top
 Profile  
 
 Post subject: Re: Why doesn't T-molding reach the sub-floor?
PostPosted: Tue May 24, 2011 11:00 pm 
Offline
Prized Contributor
User avatar

Joined: Sun May 24, 2009 7:48 pm
Posts: 1802
Location: Las Vegas
Doesn't feel right to me applying adhesive to a damp slab, just something about it. Besides the adhesive states moisture cured, not moisture stick better :mrgreen: Infact I believe they all state for the concrete to be dry.

_________________
Howard Chorpash
Frazier Mountain Hardwood
http://www.lasvegaswoodflooring.com


Top
 Profile  
 
Post new topic Reply to topic  [ 17 posts ]  Go to page 1, 2  Next

All times are UTC - 5 hours


Who is online

Users browsing this forum: No registered users and 0 guests


You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum

Search for:
Jump to:  
Powered by phpBB © 2000, 2002, 2005, 2007 phpBB Group

phpBB SEO