If these are Torlys engineered click together floors (with the HDF core) you are going to have concerns gluing down. Only if this is SOLID CORE hardwood engineered flooring can you look to glue down. The problem: HDF moves A LOT. It LOVES to expand and contract (as much as 1" over 25 linear feet....that's a LOT). The hardwood on top DOES NOT! If you glue down the HDF core product, you restrict a DYNAMIC plank. That plank will have problems. It will eventually rip itself away from the adhesive....the expansion forces will break the glue bond. And the glue is NOT grabbing the HDF....it is grabbing the CORK UNDERLAY. The cork underlay is the weakest part of the plank. Go ahead and pick at it with your nail. It crumbles after a few strokes. That's what the glue will be grabbing. It would only take one full "heating-cooling" cycle (winter-summer) for the bond to break. If you have installed floating floors with T-moldings before and "had no problems with it" then I suggest you keep going with that successful approach. Remember: "If it ain't broke; don't fix it," is something we all live by in the building industry.

Ok...so engineered hardwood is an option because this is "ground level" and not below grade. If you do not want to heavily invest in the home's flooring (and after a big renovation you feel the pinch at every turn...I get that), then an excellent water resistant laminate (I hardly need to add "out of Europe"...) will give you an amazing floor for 15-20 years without much effort. Work with something out of Switzerland or Germany and you will be ASTOUNDED by the toughness and the handsomeness of the product. Quick....do it be Brexit! While all the tariffs are still "Zero"! I like water proof/water resistant laminates because you are in IRELAND...it rains there from time to time. Sometimes water comes in on your Wellies...and that just isn't good for regular laminate or wood. As water resistant as you can please. It will pay itself back 10 fold by the time you finish your second winter with your flooring.

OK...point #1. If any part of your slab is 'below grade' the ENTIRE THING is graded as 'below grade'. Personally I would pick different flooring for the 'wet' rooms such as the bathrooms and laundry. The reason: 'water proof' flooring is expensive. So WHY pay for the entire basement to be covered in 'water proof' when only a few hundred square feet actually 'need it'. The other thing is: a floating floor is really all you want to play with. Tiles in bathrooms/laundry room can be adhered to the concrete, the rest can be floated. The basics for ANY floating floor is the same. You must have a vapour barrier (not always underpadding) and you must always have a WELL PREPARED concrete slab that is flat (no wonky subfloors for a floating floor...ever). A laminate floating floor and a vinyl floating floor and a cork floating floor (and even a linoleum floating floor) all require the same thing. And the mechanism to install is always a 'click-together' system. An engineered hardwood can be floated but it almost always requires glue on the seams. Again, all of the same PREPARATION is required. So go ahead and start paying for the concrete slab to be fixed up so that your flooring of choice can be laid down as soon as you can. The 'nightmare' the sales guys are talking about relates to installation and moisture. They are TRYING to get you to purchase the product THEY NEED to move. Yep. I would hazard a guess that these guys have been given 'targets' to meet and/or they have been offered bonuses for moving a certain TYPE of product (too much in the warehouse is costing the company TOO MUCH money). In a nutshell, the reason why you are getting 4 different opinions is because you spoke to 4 different salespeople with 4 different 'company agendas'. That's it. There is no mystery in that. My questions for you (if I were your sales person): 1. What is your budget (do NOT fudge numbers with sales people...it pisses them off and makes them less likely to get the RIGHT floor)? 2. What is your FAMILY situation? Animals? Landscaping issues such as pools, etc? 3. What are YOUR expectations? Can you accept the limitations of certain flooring if it gets you the LOOK that you want for the price you are able to pay?

What are the current floors? Do they need to be removed? Asbestos assessments done? Hickory is lovely but VERY orange/brown (you will be surrounded in wood on all 6 sides). It is also a snick more unstable (dimensional stability) than other hardwoods. It isn't the best option for a home that is vacant/empty for large parts of the year (covid not withstanding). The good thing about laminate is it is relatively cheap and easy to install. It allows for THICK corn underlay to increase heat retention in the home and it is easy to anticipate expansion/contraction without heating/cooling for long periods of time. Vinyl is tricky in situations like yours. It does NOT like wonky subfloors. It does NOT like it too hot or too cold (becomes brittle in the cold). It does NOT like direct sunlight (can warp and/or discolour). And it does NOT like any form of underpad. Carpet is an easy fix if you like it. Hardwood can be used but I would go as NARROW as you can in a species that is relatively stable (white oak is slightly better than hickory...red oak is a snick better than that). I would look at an old fashioned 2" strip hardwood. It's dimensional stability will be the saving character. Remember: the WIDTH of the plank is the START of a stable wood floor. If you START with a stable width (very narrow = very stable) you START with the best option for the living situation. I'm a fan of cork = highly appropriate for the age. But the homeowner needs to be ready for a quirky cork floor. And cork starts out orange/yellow/brown but it gets LIGHTER. Yep. You start with an orange cork floor but in 5 years you will have blonde floors. You will LOSE the 6 sided orange box. For me that's a win.