[Home](https://www.referralflooring.com/)/[Services](https://www.referralflooring.com/services)/Engineered flooring Engineered hardwood # Engineered hardwood installation: real wood, built to stay put. Engineered flooring is real wood from top to bottom, made of several layers of veneer or lumber core bonded together with the grain running in opposing directions.[1] That construction is the whole point. It moves far less than a solid board through an Ontario heating season, which is why it is the wood floor that can go on a basement slab, over radiant heat, and in wide planks. It comes in thicknesses from 3/8" to ¾", and the top layer, called the wear layer or lamella, is the species you see and the thing that decides how many times it can ever be sanded.[1] Ask for the wear-layer thickness in millimetres before you buy. It is the one number that separates products that look identical in the box. How it goes down ## Four fixing methods. The room picks the method, not the brochure. What suits a basement slab rarely suits an upper floor, and what suits a 3/8" board is wrong for a ¾" one. This is the decision the in-home estimate is for. ### Nail down Over a wood subfloor - Cleats or narrow-crown staples through the tongue - Fastener gauge and spacing depend on the board's thickness, see the schedule below - The default on main and upper floors ### Full spread glue down Slabs, and anywhere nailing is out - Adhesive trowelled across the entire subfloor - Adhesive and moisture control chosen as a system - The usual answer on a tested, dry concrete slab ### Floating The only wood floor that can - Boards lock or glue to each other, not to the floor - The guidelines are explicit: when installing a floating floor, engineered flooring is the only type of wood floor that can be used[1] - Must be free to move: nothing screwed through it, ever ### Tongue and groove glue Edge-glued, floating - Adhesive in the groove of each board, the floor floats as one panel - Same freedom-of-movement rules as any floating floor - Chosen where the product is made for it and the subfloor is flat enough The measurable part ## What the guidelines require for engineered. Quoted from the national installation guidelines, source linked beside each figure. Your product's own instructions override any general rule here, because that is what the warranty is written against. ### Where it can go Due to its construction, the guidelines state engineered wood flooring can be installed above, on or below grade.[1] Solid wood cannot go below grade unless its manufacturer says so.[1] That single line is why engineered is the wood answer for a [Canadian basement](https://www.referralflooring.com/which-flooring-to-choose). ### Fastener schedule for thinner boards For tongue-and-groove engineered flooring under 5/8" thick, the guidelines specify an 18 to 20 gauge cleat or a ¼" narrow-crown 18 gauge staple, not less than 1¼" long, at 3" to 4" intervals along each board, 1" to 2" from each end joint, minimum two fasteners per board.[1] Thicker engineered boards follow a wider schedule of 6" to 8".[1] A thin board fastened on a ¾" solid schedule is under-fastened. ### Flatness for glue-down and floating Glue-down, floating and short-fastener installations need the subfloor flat to within 3/16" over 10 feet, or 1/8" over 6 feet.[1] That is tighter than nail-down, and it is the number most quotes quietly skip. A hollow under a floating floor becomes a deflection, and a deflection becomes a broken locking edge. See [how the subfloor is brought to tolerance](https://www.referralflooring.com/subfloor-repair-and-levelling). ### Concrete gets tested Moisture testing of a new slab may begin 30 days after placement, and the guidelines are careful to add that this does not mean a 30-day-old slab is ready to receive flooring.[1] The recognised tests are in-slab relative humidity probes to ASTM F2170, calcium chloride to ASTM F1869, or calcium carbide.[1] Appropriate moisture testing is described as the only way to identify whether slab moisture is adequate for the system being used.[1] ### Over radiant heat Engineered is generally the wood for radiant heat, but not every engineered product. The guidelines note that engineered flooring with less-stable wear-layer species such as hickory, beech and maple is not normally best suited over radiant heat unless the manufacturer says otherwise.[1] The system must be fully operational, regardless of season, for a minimum of 5 days before the flooring is delivered.[1] More on the surface temperature limits in the [choosing guide](https://www.referralflooring.com/which-flooring-to-choose). Sources 1. National Wood Flooring Association, [Wood Flooring Installation Guidelines](https://nwfa.org/wp-content/uploads/2026/02/NWFA-Installation-Guidelines.pdf), revised 2025. Engineered wood flooring construction and thickness, grade-level suitability, floating-floor eligibility, fastener schedules for engineered tongue-and-groove flooring, subfloor flatness tolerances, concrete moisture testing, and radiant heat. Standards last read 9 September 2026 Related ## Read next. - [Engineered vs solid, and the basement questionThe documented differences side by side, and what goes over concrete in Canada.](https://www.referralflooring.com/which-flooring-to-choose) - [Solid hardwood installationWhen solid is the right call, and the fastener and moisture figures it has to meet.](https://www.referralflooring.com/hardwood-floor-installation) - [Hardwood over concrete or existing hardwoodWhich hardwood, and why the slab gets tested first.](https://www.referralflooring.com/what-can-go-over-an-existing-floor) - [Cabinets first, or floor first?The answer changes with the fixing method, and getting it backwards costs twice.](https://www.referralflooring.com/flooring-order-of-work) Next step ## See the wear layer and the colour in your own light. The samples come to the house with the free estimate, we look at the subfloor, and you get a firm number before we leave. [Book a free estimate](https://www.referralflooring.com/#book) [Call 289-689-4242](tel:+12896894242) Phone [289-689-4242](tel:+12896894242) Email [referralflooring@gmail.com](mailto:referralflooring@gmail.com) Warranty 1 year on floor repair and installation. Area [Burlington](https://www.referralflooring.com/flooring-burlington), [Hamilton](https://www.referralflooring.com/flooring-hamilton), [Oakville](https://www.referralflooring.com/flooring-oakville), [Grimsby](https://www.referralflooring.com/flooring-grimsby) and the [wider Golden Horseshoe](https://www.referralflooring.com/service-area). --- Source: https://www.referralflooring.com/engineered-hardwood-installation