Common questions related to bamboo floor installation
Glue down. While this is the most expensive and labor-intensive method, it is also considered the most stable method as the glue provides sound and moisture insulation, and the elasticity in the glue allows the floor to expand and contract naturally with the seasons. Our floors can be glued down to a multitude of surfaces. Be sure to check out the Acceptable Subfloor Types table in our installation instructions. If you're gluing down over plywood you can use a basic bamboo flooring glue, but if you're going over a slab you'll want to choose an all-in-one glue for bamboo flooring over concrete. Remember that it's important to use the correct trowel in tandem with the glue you've chosen. If you use the wrong trowel you may not get the correct spread rate, causing your floor to fail. This can be a very expensive mistake!
Floating. The advantage to a click-lock floating floor is the ease of installation as it is less time consuming to install. It is also easier to repair floating floors should you ever have a leak or other problem. The disadvantage is that, unless your home has stable indoor humidity year-around (meaning it stays within a 20% range indoors the whole year), you are limited in the length of the continuous runs of flooring you can lay. Across the widths of the planks (tangentially) you are limited to 25 feet with engineered floating floors and 15 feet with solid floating floors. Running down the lengths of the planks (longitudinally) you are limited to 45 feet with engineered floating floors and 25 feet with solid floating floors. For this type of installation we recommend you use a 3 in 1 underlayment.
Due to the density of strand woven flooring, we recommend only using a high PSI, high quality 18 gauge pneumatic nailer, such as a Primatech Q550 ALR or Powernail 50P Flex. These nail guns require an air compressor. You must use an 18 gauge cleat, as larger cleats will cause dimpling. Staple guns will not work on strand woven floors.
For moldings installation we require a Bostich Porter 23 gauge micro nailer or similar gun.
For all nailers, make sure cleats and nails are set properly before continuing to the next row, as failure to do so may result in goosebumps/dimpling. You may need to try several pressure/PSI settings before finding a setting that will work – test on sacrificial planks. Ensure the connector hose, seal and air compressor are fully functional and have no tears or defects.
If you do not use the correct nail gun or cleat size, you may get dimpling in your floors. Read this important document about goosebumps and dimpling in strand woven bamboo.
NAIL GUN PRESSURE TOO HIGH: ALWAYS practice on a few planks to ensure the correct PSI setting on the nail gun. If the pressure is too high the nail will split the plank. When using the mallet always use small, light taps - as opposed to large, forceful taps – this is the best to get a snug fit.
NAIL GUN PRESSURE TOO LOW: If the PSI is too low you will end up with dimpling (“goosebumps”) on the face of the floor. Always inspect for dimpling from a low angle and with backlighting after installing the first two rows, because it’s difficult to see when standing directly over the area. It is the responsibility of the installer to check each row after it has been nailed down to ensure all cleats are sufficiently embedded in the planks so they don't cause dimpling in the finished floor upon fastening successive rows.
NAIL GUN PRESSURE JUST RIGHT: You will know that the pressure is just right when the cleat is flush or slightly below the surface of the tongue.
Tongues are slightly splitting – that is okay!
When nailing down extremely dense hardwoods like strand bamboo and eucalyptus there is a chance that the tongue on the planks will crack or split when the cleat is driven in. As long as less than 30% of the cleats have splitting around them, and the splitting is minor, this is perfectly normal and is not considered a defect (your floor will still be covered under the warranty if this happens) as the cleat is still firmly driven into the rest of the board keeping it securely in place. When splitting is happening try to use less force when striking the nailer with the mallet. Below is an image showing acceptable splitting, if occuring on less than 30% of the planks.
Do not acclimate the floors on top of concrete, carpet with concrete under it, crawl spaces or any other sub-floor that may contain moisture, without first laying a 6 mil polyethelyne plastic barrier down, or the flooring will soak up the moisture from the concrete and shrink post-installation. Make sure to extend the apron/border of the plastic barrier at least 18 inches beyond the flooring boxes.
First, stack the boxes up to 5 high, with each stack located at least 3 feet away from the next. Cross-stacking is preferable if you have the space. Once the boxes are stacked, use a box cutter or sharp knife to cut each box down one entire side lengthwise, and also the end flaps. Make sure to also cut open the interior plastic so that the floors really breathe.
Ensure that the flooring is acclimated in an environment (temperature + humidity) that will closely match the environment in which the floor will used in. Remember that you must keep your interior humidity settings between 40%-60% (as for all wood floors) or you may experience increased expansion and contraction.
We recommend ordering 10% extra for cutting and waste. If you have one or two large rooms that are square, and you are careful making cuts, you can probably get away with 7%. If you will be installing the flooring diagonally then it is likely you will need 15% extra for waste.
Also keep in mind that bamboo/hardwood floors come in unique dye lots so it is a good idea to hold on to a few extra boxes in case you ever need to make a repair down the line. The extra boxes can be stored in an attic, basement or even a garage, just remember to acclimate all floors prior to installation, for at least 72 hours, within the environment in which they’re going to live.
1) If you're gluing the floor down to plywood or any other approved substrate, you'll want to use a zero VOC 100% urethane trowel-down adhesive approved for wood flooring installation. When installing over plywood you don’t need glue that contains a moisture barrier unless there is a crawl space, garage or other moist environment underneath. If this is the case make sure to follow our installation instructions which provide a complete set of floor prep guidelines.
2) If you're gluing the floor down to concrete or any other sub-floor that may be emitting moisture, most of these cases will require an adhesive that contains a moisture barrier. These adhesives are slightly more expensive than basic adhesives but well-worth the investment. We sell a great zero VOC adhesive with moisture barrier that works not only for bamboo but for all types of wood floors and even some tile, and it comes with the bonus of also having a sound barrier, so many of our clients use it on their upstairs floors to keep noise levels down. Important: always make sure to use the the correct trowel style and size for the type of adhesive you select or you may not get enough coverage on the floor and this will cause the installation to fail.
About Moisture In Concrete. Most concrete slabs emit moisture for up to 25 years after being poured, and installing a floor over such a slab is easy to do, however as with any other job done right you want to make sure you have the right tools, and adhesive, on hand. Moisture is measured in pounds on concrete slabs. Basic adhesives usually protect up to about 3 pounds of moisture. Meaning, if you test the concrete and it comes back higher than 3, you need an adhesive that contains a moisture barrier.
Keep in mind that moisture tests only test the moisture on any given day. A slab may read 8 lbs per square foot one day but then it rains for a week and the moisture rating jumps to 14. Our glue with moisture barrier mentioned above protects your floor up to 15 pounds of moisture per square foot which is very high and usually more than enough for all jobs. There are also unlimited vapor barrier glues on the market but they are very expensive and typically only used for "wet" slabs.
As to the direction of the flooring planks in relation to the joists below the sub-floor, this depends on several factors mostly related to the current condition of the sub-floor. If the subfloor is observed to be sagging, it is recommended that you install the planks in a perpendicular direction compared to the joists. This is a call you'll want your installer to make as he/she will need to inspect the sub-floor prior to installation.
Important Note About Crawl Spaces: Many wood floors fail due to the failure of the installer to address moisture in crawl spaces. If you have a crawl space under your home or new flooring, you must properly remedy this moisture.
You must have a high quality vapor barrier or moisture insulation (with 100% blockage) or the moisture coming up from the crawl space will damage the flooring. A ground layer cover is required - must be 6 mil minimum black polyethylene with joints overlapping at least 6 inches, and sealed with moisture-resistant tape.There must be a minimum of 18′′ from the ground to underside of joists, the polyethelene should also extend at least 6" up the block walls and be sealed there as well, and it should have perimeter venting equal to at least 1.5% of the crawl space total square footage. The vents should be properly placed for cross-ventilation. We recommend you read this document about what happens when crawl spaces are not sealed.
Important Note About Installing Over An Unconditioned Space (such as a garage): Subfloor moisture penetration of improperly sealed sub-floors over unconditioned spaces is a common cause of wood floor failure. If you are gluing the floor down over such a space, you must use a 100% urethane adhesive that contains a moisture barrier. If you are nailing the floor down over such a space, you will need to follow these steps:
In an unfinished space, staple a 6 mil plastic sheet to the ceiling of the unconditioned space with joints overlapping at least 6 inches, and seal with moisture-resistant tape. In a finished space, coat the ceiling with two layers of high-gloss paint.
Lay down two layers of 15 lb asphalt saturated felt paper at a 90 degree angle to each other over the plywood before beginning the nail down installation. Thus, lay down the first layer and be careful not to overlap the rolls as this may cause an un-level surface. Once the first layer is down, install the second layer at a 90 degree angle and care not to overlap
On a floor that is nailed down or glued down we recommend that you do not place furniture that exceeds 2,000 lbs or the maximum load your joists will hold, of which it is the installer's responsibility to determine.
However with floating floors there are a few exceptions as to what you can set on them. A piano is fine. A piece of furniture with legs, or with just a few points of contact with the floor, is fine. For pieces of furniture without legs - is the piece of furniture flat across the bottom, and how long is it in comparison to the run of flooring it will sit on? The reason we ask is, in a floating installation you want to avoid "pinning" a long row of successive flooring planks across the widths of the planks, and more so if that run of planks takes up a large section of the overall run. This is more applicable across the widths of the planks (tangentially) than down the lengths of the planks (longitudinally).
The floor needs to expand and contract during seasonal cycles, and pinning the planks down will inhibit this movement and may cause gaps to form between the planks. This is why, for example, we don't recommend installation of floating flooring under kitchen cabinets. If the bottom of the furniture is flat and it stretches across the widths of the planks for more than 50% of that given run, and it's over 200 lbs, we suggest gluing or nailing the floor down. Otherwise you'll be fine.
Our solid (wood all the way through) floors can be put under cabinets if they are being nailed down or glued down. Floating floors of any kind should not be installed under cabinets. This is because you do not want to pin down an entire side of a room of floating floors as it will inhibit their ability to expand and contract naturally.
Some general sub-floor requirements:
Must be structurally sound
Must be clean - thoroughly swept and free of all debris
Must be level - flat to 3/16" per 10-foot radius
Must be dry - subfloor must remain dry year-round. The moisture content of a wood subfloor must not exceed 12%. Concrete subfloors and crawl spaces need to be addressed with a vapor barrier.
Important note about Gypcrete: Gypcrete will sometimes exhibit a layer of debris that floats to the surface while being poured. This is usually obvious and if it occurs will need to be removed with coarse open grit paper on a buffer until a solid surface is reached. You will then use a diluted coat of acrylic primer to seal the surface; however, it must soak in and not leave a film. Once the gypcrete is prepped and primed you can proceed with a normal installation.
A note about Lauan/Luan/Luaun: While most urethane adhesives bond to Luan and thus you could glue our floors down to it, Luan is generally considered an unstable substrate for tile or hardwood flooring. It doesn’t have much strength, so it may contribute to squeaking or bouncing. Our recommendation is always to remove it before installing a new floor.
Wood subfloors must be dry and well secured. For nail-down installations, nail or screw every 6" along joists to avoid squeaking. If the subfloor is not level, sand down high spots and fill low spots with an underlayment patch or self-leveler such as Bostik Duralevel 83P Self-Leveling Underlayment.
Concrete must be fully cured, at least for 60 days. If it is not level, grind down high spots and fill low spots with leveling compound. The concrete must be flat to 3/16" per 10- foot radius. All concrete must be tested for moisture and the appropriate vapor barrier urethane adhesive must be used to account for the moisture emission level. We recommend reading our full installation guide for details.
Properly manufactured bamboo and eucalyptus floors (like ours!) are similar to mid-range hardwoods when it comes to dimensional stability, so they can be installed in all climates whether very dry or very humid. Our floors have been installed around the world from the jungles of Kenya to the heights of the Rockies.
All wood flooring expands and contracts with the seasons due to changes in humidity - there are no exceptions. The key is to control your interior humidity as to avoid excessive swings in humidity throughout the year, as these will cause expansion and contraction in your wood/bamboo. The recommended humidity setting for our floors is 40%-60% in humid climates and 35%-55% in dry climates but even dryer and more humid settings may suffice as long as your humidity is stable (within a 20% range) throughout the year. We do recommend to try to keep the humidity above 25% in almost all cases. In very humid or very dry climates, just follow these tips and you will be all set:
a. Acclimate your flooring for at least 10-14 days prior to installation (instead of the normal 72 hours) in the environment in which they are going to be lived on. Ensure all boxes are opened properly so that the planks can breathe.
b. Glue the flooring down. The elasticity in the glue allows the floors to breathe easily through humidity changes.
c. Make sure to leave ¼ - ½ inch of expansion gap around your flooring perimeter at the time of installation.
d. Try to keep your interior humidity setting consistently in the same 20% range year round (opening windows for a day won't hurt the floors), even via the use of humidifiers/dehumidifiers if necessary. If you allow big humidity swings, larger gaps may develop between your planks during dry spells and they'll close during wet spells.
We highly recommend reading our post about installing bamboo flooring in humid and dry climates too.
And here's a good article about installation: glue down vs nail down vs floating.
*Please note that these are general guidelines. Please contact your radiant heat system manufacturer prior to installation to ensure that your specific system is compatible with bamboo flooring as well as if they have any specific requirements.
** Please note that solid floors must be glued down using a vapor lock glue and that the thickness/spread rate must by at least 2mm of glue.
***We strongly recommend that you read the NWFA Radiant Heat Protocol prior to beginning your floor planning.
PRIOR TO INSTALLATION – RADIANT HEAT SUBFLOORS
If the radiant heat system is embedded in concrete, turn the radiant heat system on with the temperature set on high for 5-6 days. The should help burn off any moisture residing in the concrete prior to installation and this should be done the week leading up to installation. Next, the temperature should be set to 65° F and held at that temperature 24 hours prior to acclimating the floors – during acclimation – during installation – and for 72 hours after installation.
- Make sure to leave 1/4" - 1/2" of expansion space between the flooring and the walls.
- The temperature of the radiant heat system should always be maintained at a constant 65° F.
- A stove or any other item that can affect the temperature of the ground should not be used at the job site.
- The flooring must be acclimated over the radiant heat with the system turned on and set to 65° F. The same acclimation preparation must be followed as always, including cutting the boxes open and stacking them as prescribed in the Acclimation section of this document.
- If the radiant heat system is encased in concrete or another substrate that releases moisture, a 6 mil polyethelene barrier must be placed between the flooring boxes and the substrate so that the flooring does not absorb moisture during acclimation.
- We require at least a 2mm foam or resilient 3 in 1 underlayment pad be installed over the radiant heat system prior to the installation of the bamboo flooring.
AFTER INSTALLATION / MAINTENANCE
- During the first three days after installation, the radiant heat system temperature should be maintained at a temperature of 65° F. After that, the temperature can be set warmer, by 1.5° F each day.
- The temperature of the sub-floor must never exceed 85° F.
- When turning off the radiant heat system, it must cool by a temperature of 1.5° Fahrenheit per day. Never turn your radiant system off suddenly.
- The radiant heat system cannot fluctuate in temperature rapidly. Room temperature should vary no more than +/-7 degrees Fahrenheit year around.
- Slight changing of color is expected for bamboo flooring installed over a radiant heating systems.
- Radiant heat systems, even when set at a reasonable temperature, can draw moisture out of wood floors. A humidification system might be necessary to ensure the flooring stays in its stable zone.
Some adhesives will fail spectacularly if you use the incorrect trowel size and design, so using the correct trowel(s) is a must. We currently sell two types: 1/4" x 1/8” Square notch for our basic adhesive and 1/4" x 1/4" V-Notch for our vapor and sound barrier adhesive. The V-Notch is designed to give 100% coverage of adhesive so you have a complete layer/seal on the slab. Don’t skimp when you’re troweling down vapor barrier glue!
The Square notch trowel does not give full coverage but puts down enough glue for 85% coverage, enough to hold down the floor on plywood or places where sound and moisture barriers are not needed. Square notch trowels typically yield about 140 feet per pail and V notch trowels typically yield about 125 feet per pail.
Most squeaky floors are the result of the house settling and the lumber drying out and shrinking, or the sub-floor nails having come loose over years of seasonal expansion and contraction cycles, resulting in the structural wood parts rubbing up against each other and/or the nails. Loose sub-flooring will emit high frequency chirping noises.
There are several ways to remedy this issue, including drilling screws up under the sub-floor to tighten the lumber up against each other. We suggest that you consult with a local flooring installer to review all options, as some are dependent on how your flooring is installed.
Our flooring has been installed around the world and in many different types of structures such as homes, restaurants, libraries and more, but it is only warranted for indoor use and when installed according to our bamboo flooring installation guidelines.
There should be at least 8 inches between where two butt ends of planks meet, in adjacent rows. This means that no starter row plank should be cut to less than 8 inches in length.
Most prefinished wood floors are packaged shortly after coming off the finish line, and what you smell is actually slight off-gassing from the polyurethane finish; however there is no need for worry. These are not harmful emissions and within 2-4 days the odor will disappear. If you don’t like the smell we suggest that you open a few windows to air the room out.
The U.S. Green Building Council actually ranks varnish and lacquer as two of the worst offenders in terms of VOC off-gassing, so your wood furniture may be emitting more than your wood floors. Federal laws call for varnishes to include less than 450 grams of VOCs per liter, and they require less then 350 grams per liter for lacquers.
All of our products meet the CARB Phase 2 indoor air standard and we test them on a yearly basis, at random, using a third party U.S. laboratory. You can see all of our test results here: https://www.ambientbp.com/urea-formaldehyde-free-bamboo-flooring.php
We recommend that you only use 18 gauge cleats. If you use 16 gauge cleats they are likely to cause dimpling on your floors, as described in this article: https://www.ambientbp.com/pdf/avoiddimpling.pdf
Furthermore, they may cause cracks and splits in the tongue that will cause further issues down the road.
Bamboo and hardwood floors should be kept at least 18-24 inches away from high-heat sources or the heat can dry them out and cause irreparable shrinkage. Here are 2 rules of thumb to follow and you should be okay:
1. Install the bamboo flooring at least 2 feet away from the stove by putting in an apron of brick/stone/similar around the stove.
2. Acclimate the bamboo flooring that will be installed near the stove in the same area where it will be installed, with the stove turned on (no closer and no farther than where it will be installed).
3 in 1 underlayments should not be used when nailing down a floor. These underlayments are nullified as a vapor barrier once you nail through them, and the compression of the foam results in loosening of the cleats over time.
Yes, you can store flooring boxes in a covered area outside of the home under the following conditions:
Remember, storing boxes in a garage or non-climate controlled space is not considered acclimation. In fact, for floors that are stored in a garage/shed first, we recommend acclimating them at least 2-3 extra days on top of the normal acclimation period. The boxes will still need to be brought into the space in which they're going to be installed first (for acclimation) as per our installation instructions.
All types of engineered bamboo flooring can be installed below grade, but it is not recommended that solid hardwood or bamboo flooring be installed below grade. When installed via the floating method, we recommend the use of a quality 3 in 1 underlayment to serve as a moisture barrier and for footfall noise reduction. Engineered floors can be installed via the glue down method on any level of the home, but if installing over concrete or a crawl space you must use a urethane flooring adhesive that contains a vapor barrier (all-in-one glue).
Remember that you'll want to acclimate the floors in the same room in which they're going to be installed at least 72 hours prior to installation, and be careful not to acclimate them directly on concrete or over crawl spaces as they will absorb moisture, which will cause problems. Instead, ensure to lay down an 8 mil thick plastic sheet or 3 in 1 underlayment for the boxes to sit on during acclimation, and you'll want the apron of the sheet to extend about 1 foot away from the boxes themselves for added protection. The interior humidity settings of the basement must be maintained between 40%-60% just like on any other level in the home.
We do not recommend installers. However, you have several options available to you to locate a good installer:
If you have a humidity modulator in your home that will successfully and constantly keep your indoor humidity at a level of 40%-60%, you do not have any run limits on your floating wood floor. This humidity range can also be achieved via the use of a portable humidifer or dehumidifier. Also, some areas in the Southern United States have relatively stable humidity year around (like Southern California or Florida) so this usually isn't an issue in those areas.
However, if you live in an area with distinct seasons and wide variance in humidity and you don't have a way to control your humidity, you'll need to be careful with your run limits. We recommend reading our flooring installation guidelines in all cases.
You will want to make sure to use an adhesive that specifies it will bond to both surfaces. Most adhesives will not bond to either the vinyl or the PVC so ideally you want something that will bond to most surfaces like this product from Liquid Nails.
Due to the nature of strand woven bamboo and eucalyptus it is difficult to achieve accurate moisture readings from the variety of moisture meters that exist on the market today, so we don't require testing the flooring before the installation. You will however want to make sure the floors have been stored in a dry, covered area and have not been left out in freezing temperatures for more than 24 hours.
Our floors are already optimized for moisture content to be acclimated and installed almost anywhere in the world. We do however require that testing be performed on the subfloor to ensure it's not emitting more than 12% humidity/moisture before, during and after installation.
The installer/homeowner must also ensure that they acclimate and maintain the flooring in conditions between 35%-55%. Please note that to acclimate flooring on to of concrete or an unsealed crawl space you must first lay down a (minimum) 8 mm polyethylene tarp or similar vapor barrier under the acclimating boxes, with the apron of the vapor barrier extending out at least 18 inches from the opened boxes. (This is to prevent the flooring from absorbing moisture while acclimating).
The short answer is – it depends on a lot of factors! There are many different concrete and cement products from various manufacturers on the market today. Because the components are going to differ from product to product, there is no set time frame. Although, the product manufacturer should have instructions that may list drying or curing times. Other big factors are the humidity levels, temperature, and whether or not you have fans blowing as those can all affect curing times.
The best way to determine if the subfloor is ready to be glued down to is to conduct a calcium chloride test to ensure the vapor emission from the subfloor in question does not exceed the upper moisture limit of the adhesive you plan on using. Take for example our very own Bilder’s Ultimate adhesive, which is warranted on slabs with moisture emissions up to 20 lbs (per 1,000 square feet). That means if your calcium chloride test results come back under 20 lbs (per 1,000 square feet), then you are good to go! But let us say your test results came back at 6 lbs (per 1,000 square feet) but your adhesive is only rated for 3 lbs (per 1,000 square feet), then your floors are very likely to cup as the moisture in the slab exceeds the capabilities of the adhesive.
Typically, if the finished basement is climate controlled, you do not need a moisture barrier in between the subfloor and the new floor you are installing. However, some basements can emit excessive humidity – upwards of 70%. To be sure, we recommend testing the humidity with a hygrometer to get an accurate idea of the indoor air humidity, and you can also test the humidity on the main grade sub-floor itself. If excessive moisture is coming up from the basement you have a few options. The first is to glue down the floor using an adhesive with a vapor barrier. The second option is to choose a click-lock floating floor, so you could float the floor on top of a 3 in 1 vapor barrier underlayment. Both of these will seal off your floor and protect it from any sub-floor moisture.
Adhesive remover wipes are designed to clean up wet adhesive before it dries. Wet glue is much more difficult to remove with soap and water, but the wipes have a special compound that helps to break down the glue.
Once flooring adhesive dries it is impossible to remove and will irreparably damage your floor finish as the topcoats will be stripped away when you remove the dried glue. Absolutely never use mineral spirits to remove any glue from our floors as mineral spirits will damage uv cured urethane finishes If adhesive dries on your finish we advise that you dump some of the Adhesive Remover liquid on the spot, let it sit for 10 minutes and then use a Mr. Clean Magic Eraser. This can get in the pores of the finish and get most of the glue off, but there is no guarantee that you may still damage the floor finish itself.
Cupping can happen for several reasons, but the #1 culprit is installer error or improper maintenance of environmental conditions onsite. Cupping is usually caused by elevated moisture content rising from the sub-floor and hitting the bottom of the flooring planks. Moisture affects the sides of the plank quicker than the center, causing them to swell and form the “cup” shape. There are many causes including improper flooring adhesive, incorrect trowel with the wrong spread rate, improper acclimation of the floor prior to installation, and many more. If you follow our installation and maintenance guides, you should not experience any of these issues.
Some cupping can be considered normal on wide planks, but if it is significant, there is usually an underlying issue. Important things to look out for:
1) The flooring was installed over a crawl space that wasn't properly sealed and the humidity is coming up through the subfloor and hitting the wood/bamboo floor.
2) The bamboo flooring was glued down to a concrete slab but the glue wasn't troweled down properly (either wrong trowel was used or there isn't full coverage on the slab) and there are gaps in the glue, so the moisture being released by the slab is hitting the bottom of the wood/bamboo floor. Different glues have different moisture barriers (3 lbs, 5 lbs, and 12 lbs are common) and you will need to use one with a high enough barrier for your subfloor.
3) The flooring wasn't acclimated properly so now the wood has adjusted and it's now it's drying out and changing shape.
4) Dry cupping: when a homeowner leaves the home and turns off the hvac, it can result in what is called the "Green House Effect" in summer time. Excessive heat and humidity followed by air conditioning will cause cupping.
Below are a few good links for further reading:
It is the responsibility of you or your installer to determine whether the glue brand you are using with our floors will suffice, and we do not recommend nor reject specific brands. You should be able to place a quick call to the glue manufacturer you are considering to determine whether it can be used in conjunction with hardwood and bamboo flooring.
Using a glue other than those we sell will not void your floor warranty per se as our warranty covers our floors, not the tools or materials used to install them. If the floor fails later and the reason is because it was improperly installed or the glue failed, this should be covered by the labor warranty or glue warranty.
We strongly suggest only hiring an installers that provide a 1 year warranty on their labor as most flooring issues arise within the first 10 months after installation.
Gapping in hardwood floors is normal wood behavior and dry, cold days can cause this; in summer when the humidity increases and the planks swell, the gaps may or may not close up. This is normal and to be expected as wood is a hygroscopic material that expands and contracts to balance itself out with the humidity in its environment.
Check your humidity levels using a hygrometer and if your humidity is at or below 35% we recommend turning on a humidifier to remedy the solution. If gapping exists but humidity levels are between 40%-60% (recommended humidity range for hardwood and bamboo) it may be a result of improper acclimation or an uneven subfloor (where the planks are “sliding” down opposite sides of a mound due to repeated foot traffic), or the humidity was allowed to drop below 30% in which case the gaps may be permanent.
The National Wood Flooring Association recommends that you maintain a range of around 40%-60% humidity levels in your home if you have any wood floor installed. Here is some further reading you can do on the topic: