Attaching a wooden threshold to a concrete floor

[abgoto]

I volunteered to build a custom threshold for a local charity.  Doorway is 900mm wide steel frame with terrazzo on one side and a click lock oak floor on the other.  The terrazzo is 19mm deep, the click lock floor is 13mm deep and the span between the two is concrete and 150mm wide.  I've used a grinder and a straight edge to even out the terrazzo edge and leveled the concrete as best I can with vinyl cement.  My idea is a 19mm thick, 180mm wide oak transition that is flush with the terrazzo floor, and routed out on the bottom to overhang the click lock floor.  I'm stuck on how to attach the transition.  One way would be to counter sink masonry screws (tap-cons) and use wood plugs to hide the screw heads.  Another way would be to use Loctite Power Grab to attach the threshold directly to the concrete part of the floor.  The later solution is preferable because I can install it and be done (I think).  The wood plugs would involve some chisel work and return trips to stain and urethane them.  I'm concerned about the Loctite being strong enough over time to hold the transition in place.  Any input would be greatly appreciated.

 

[rizzoa13]

A 2-part epoxy may be a good solution you can attach anything to anything with that stuff.

 

[Mitchwood]

I use Sika adhesive to attach thresholds and parquet blocks to concrete, in the UK it is usually Sika T 52 adhesive, although others Sika products are available. Sika do a range of adhesive for wood flooring. The adhesive is flexible so will allow the wood to move (expand and contract). Suggest you take a look at www.usa.sika.com. You should find a suitable adhesive.

 

[Theshipstore]

I would think PL Premiumn would work on this, it's holding powers have been used by me on various concrete and tile jobs.

 

[waho6o9]

Never had luck with tap cons, epoxy or

sika would be my vote.

I always wondered if there should be a

moisture barrier there.

 

[jmbfestool]

I agree with Mitchwood.

A sika adhesive would be the way to go.

Or fixall or sticks like shi*t or stixall all are a polymer glue which will work perfectly fine.

They all stay flexible.  The fixall or sticks like or stixall are water proof.

Might be wrong but the power grap sounds like a pink grip which is a. ....... type of adhesive.  Can't remember will have to google it.
Which sets hard and is rubbish.  Still don't know why people buy the stuff.

 

[jmbfestool]

We'll just googled Loctite Power Grab from what I found its very much like the UK pink grip. 

The shape of the tube and the shape of the nozzles is the same and the descriptions are similar say instant bond no nails etc.

These kind of adhesive are rubbish have a extremely poor bond to dusty surfaces like concrete and very smooth surfaces.  They form a skin very quickly and are to thick which can often stop you getting your piece right up.  They don't like moisture and they set hard.

I don't know what branded polymers are available in the USA but either get a polymer glue or flexible flooring adhesive like Sika 

 

[galwaydude18@gmail.com]

ya I hate things like gripfill. But then again I find products like stixall etc. are very messy when it gets on your hands etc.

 

[Walk On Wood]

I do thresholds over concrete all the time.  I would hammer drill the concrete, insert mollies, and screw the threshold down with brass or stainless screws, countersinking the heads flush with top of threshold.  A little dab of a polyurethane or silane adhesive to help hold it down wouldnt hurt either.

 

[roblg3]

You could always countersink the screw heads and use wood plugs over the screw heads.  They'll be nearly invisible if you take anytime to grainmatch

 

[abgoto]

Many thanks for all the reply's.  I've never heard of Sika, but will check it out.  Thanks for warning me off of the Loctite. 

 

[xtrememtnbiker]

Just installed some T transition strips in a basement between wood and carpet. We just inserted 1/4" masonry anchors and used brass, countersunk head, robertson screws instead of what came in the pack which were silver, pan head, phillips.

 

[jmarkflesher]

I would talk them out of a wooden threshold. Use a stone or like product flush with the terrazzo on one side and cut out underneath to lay on the wood floor. Use a copper hemmed flashing strip between the stone and the wooden floor. Stone to be lightly tapered at wooden floor side. Just an idea. MARK

 

[abgoto]

Use a stone or like product flush with the terrazzo on one side and cut out underneath to lay on the wood floor.

That sounds beautiful, and would work.  Two issues:  One, I'm donating my time and materials and I'm guessing that stone is more expensive than the wood I have already purchased.  Two, I don't have tools for or experience with stone.

I went with a wood threshold and a polyurethane adhesive.  The fit is tight enough that I don't think it's going anywhere.  If for some reason, the adhesive does not hold, I can always go back with a hammer drill. 

Thanks again to all for your advice.

 

[roblg3]

The poly glue should do fine.

 

[festooltim]

I just used some of the Sika poly adhesive from Home Depot first time I have used it. This wasn't my idea but they wanted to glue a piece of cement siding to the block wall of this room we did to make a band around it. Not sure how it will hold over time but it sure seems like I is stuck pretty good for now. This is on exterior so it has to take some weather changes.

 

[sae]

Thanks for those pics, Tim. I have a block garage that I've been contemplated sprucing up, that trim looks like it would be a simple addition. Do you mind sharing where you/they sourced the material?

 

[chrismorrow]

I just replaced a threshold on concrete a couple of weeks ago.  The top of the threshold was aluminum, but it was supported under it by a 1x3 piece of wood.  After cleaning the concrete, I used Liquid Nails adhesive on the wood and around the perimeter of the threshold.  I placed some weight on the threshold for about an hour.  After the adhesive cured a bit, I caulked the outermost perimeter with exterior caulk.  This hid the adhesive on the edge, and provided some leak protection.  It looks great, and feels very solid.  I'm 250lbs.  It doesn't move when I stand/walk on it.

 

[festooltim]

Sae
The band was just 9 1/4" Hardie siding. It's about 5/16" thick. You can get the cement siding at big box stores but the wider smooth siding might be special order.

 

[Floorman70]

I volunteered to build a custom threshold for a local charity.  Doorway is 900mm wide steel frame with terrazzo on one side and a click lock oak floor on the other.  The terrazzo is 19mm deep, the click lock floor is 13mm deep and the span between the two is concrete and 150mm wide.  I've used a grinder and a straight edge to even out the terrazzo edge and leveled the concrete as best I can with vinyl cement.  My idea is a 19mm thick, 180mm wide oak transition that is flush with the terrazzo floor, and routed out on the bottom to overhang the click lock floor.  I'm stuck on how to attach the transition.  One way would be to counter sink masonry screws (tap-cons) and use wood plugs to hide the screw heads.  Another way would be to use Loctite Power Grab to attach the threshold directly to the concrete part of the floor.  The later solution is preferable because I can install it and be done (I think).  The wood plugs would involve some chisel work and return trips to stain and urethane them.  I'm concerned about the Loctite being strong enough over time to hold the transition in place.  Any input would be greatly appreciated.

Just one thing to keep in mind,avoid filling the gap between the clicklock and terrazzo,to allow for expansion