By following our check list you can avoid problems like this
I thought I'd write a check list to help general contractors, builders or DIY home owners address some of the basic issues regarding hardwood flooring installation.

1. Plywood sub-floor
  • For nail down installations (engineered or solid wood) use STD Douglas Fir plywood     
  • Minimum plywood thickness should be 5/8”
  • We don't recommend OSB (oriented strand board) for nail-down installations because we don't believe it provides the same holding power as plywood.

2. Sub-floor 'flatness'
  • Should be 3mm + or – over 10’ (concrete or plywood)
        For plywood sub-floors
                - Level the plywood sub-floor by sanding off high spots and building up low spots with layers
                  of 1/8" or 3/8" thick plywood as necessary. Glue and nail, or staple the extra layers of plywood
                  into place.

        For concrete sub-floors
               - Grind down high spots and use cement leveling compound to fill in low areas.  Use best quality
                 cementitious leveling compounds with an acrylic additive for flooring that is to be glued down.
                 Less expensive self leveling products can be used for floating floors.

3. Sub-floor moisture
  • The maximum moisture content in the plywood sub-floor should be 12%. The difference in                           moisture content between the plywood and the hardwood should be no more than 4%.
  • Concrete moisture content should be no more than 3lbs of vapor emissions per 1000sqft.                               Use a Calcium Chloride test (ASTM F1869) or RH test (ASTM F2170) to confirm this.
  • Installing solid wood flooring over a crawl space or car port or garage risks excessive                                     shrinkage and expansion.
  • Always use a moisture barrier when installing wood flooring on concrete which is at or below                         ground level.

4. Site Conditions
  • Never acclimate the wood flooring on site without confirming the sub-floor is dry, the space is heated to 20c, and the relative humidity is between 40% and 60%.
  • Ensure the space to receive the hardwood flooring is at lock-up stage (protected from the outside elements) and has the main heat on before delivering the flooring to site.                      

5. Hardwood flooring moisture content
  • Should be approximately 8%.

6. For nail down installation
  • Nail or staple the hardwood every 6” to 8” when installing over plywood.

7. Reducing squeaks/tighten the sub-floor
  • Re-screw old sub-floors with 2” or 3” decking screws before installing the hardwood flooring.

8. Relative humidity in the house
  • Should be between 40 and 60% before the wood flooring is delivered.

9. House temperature

  • Should be at 20c before wood flooring is delivered.

10. Trades using water in their product (i.e. tile and drywall)
  • Work must be completed before the hardwood flooring can be shipped to site.

All of this information and more can be found in the National Floor Covering Association's 'Floor Covering Reference Manual' -  a fantastic source of information for floor covering installations. You can buy this manual on line at http://www.mfcsi.com/reference-manual.html

Note: ALWAYS read the installation guidelines or instructions that come with the product you have purchased.  Those instructions should supersede any instructions given above.  Avoid purchasing your flooring from an auction because of potential milling, moisture content and warranty issues.  Hardwood flooring problems are expensive to fix (if they can be corrected at all), choose a product and installation firm that has a good reputation and offers a real warranty.

acoustical sound underlay, hardwood flooring sound barrier
Noisy neighbors and hard surface flooring don't mix. 

You can, however, reduce noise transference by using 'sound absorbing underlay' for floating hardwood or laminate floors.

Here are some general points about sound-absorbing underlays that may help you with your purchase decision:

Make sure that the underlay you choose has been tested using ASTM International (formerly American Society for Testing and Materials) standards .  Ask for paperwork that substantiates the underlay manufacturer's claims of the product's sound absorbing qualities. The product should have been tested in accordance with ASTM E-492.

The test results should show a couple of things....

1. An IIC (impact insulation class) rating
This is the number used to rate the sound absorbing characteristics of the underlay when noise produced from a test impact is measured.  The higher the rating the better the product is at absorbing sound.  Most products on the market have an IIC of between 60 and 75.

2. An STC (sound transmission class) rating
This measures a building material's (in this case underlay) ability to absorb audible noise such as voices or TV sound.  Most products on the market have an STC in the high 60's.

I tell my customers that 90% of the noise problems in condos exist because of lifestyle.  If you have a noisy lifestyle, then your neighbors will hear you. There is not a sound absorbing underlay on the market that is going to stop clacks and bangs, or noise from loud TV's from transferring through walls or wood flooring to neighboring suites.  Yes, a high density foam underlay with a good IIC rating will reduce the noise transference but it will not eliminate it. 

With this in mind, strata councils or building managers put rules in place (by-laws) that require a high IIC rated underlay be used for any new wood or laminate floor installations.  By doing this, they can say they made a reasonable effort to keep noise transmissions to a minimum should there be a complaint.

In some cases, just to keep the peace between neighbors, by-laws go further and demand that for example, 60% of the new hardwood or laminate flooring be covered with area rugs.  If you've ever lived beneath noisy people who have hardwood flooring you will understand why.

My advice....keep it simple.

1. Check your building's by-laws regarding sound barrier and IIC / STC requirements for hard surface flooring before installing your new floor.  In this case, it's better to ask permission than beg forgiveness!

2. Set expectations - living creates noise!  If you have a couple of active kids, play the piano, wear shoes that clack on the floor as you walk around the apartment, walk with heavy foot falls, you drop things, you like your stereo or TV sound turned up louder than most - then you are going to be heard by your neighbors.

3. Use area rugs to help reduce noise.

4. Do not nail wood flooring to an acoustical underlay.  This allows for too much movement in the wood floor pieces and will likely lead to squeaks and gaps.  Also, nails or staples facilitate sound transference similar to that of a tuning fork.  If you are nailing the flooring to a wooden sub-floor and want to insulate against sound transmission, then you will need an altogether different kind of sound barrier system - it's time to consult an architect or experienced builder.

If you live in a wood frame building with no acoustical concrete topping between floors, a sound absorbing underlay with the highest IIC rating, will not prevent sound transference.  Most underlays achieve their IIC and STC ratings from testing over concrete sub-floors. Wood frame construction and plywood substrates are notoriously bad at muffling sound and none of the products that I know of on the market are going to change that.

Hi-rise concrete buildings are best for natural noise containment because concrete is a great sound barrier.  Most hi-rise construction consists of 6" to 8" of concrete sub-floor between you and your neighbors below.

With all this said, a few underlay recommendations that are readily available and that I consider to be good value sound barriers for a floating floor installation are:

1. Dura-son
2. Sound Blocker
3. Floor muffler
4. Cork

There are many more on the market to choose from.  Check that the IIC and the STC ratings comply with your bylaws, and make sure that the IIC rating given to the product was gained using ASTM E-492.

Radiant heat and hardwood flooring diagram
It happens more often than you would think.

I was called out to measure a hardwood flooring project for a new custom-built home being constructed by a local builder. The builder wanted over 3000 square feet of solid, unfinished, quarter sawn nail-down, oak flooring installed, sanded and finished.
I reviewed the job site with the builder. He described the sub-floor as being 3/4" standard douglas fir plywood that he had glued and screwed to sleepers. The heating system was hot water radiant heating set in concrete (as shown in the cross section picture). 

I measured the square footage and took my moisture tests.  It showed the plywood was dry at 11 - 12% moisture content. This is exactly what is recommended.  I went back to the office, wrote up my quotation and faxed it to the builder.  Two weeks later, I was awarded the job and asked to go back to the job site to measure an additional room.

It turned out to be a stroke of luck that I had to return to the site.  While I was there, I did another moisture test. The reading was now 18% in the plywood.  I went into the other areas of the house that I had tested two weeks prior, and all were reading 18% plus moisture content. 

What was going on?

The builder had poured the concrete over his radiant heat piping and up to the top of the sleepers in the correct way, but had not allowed the concrete enough time to dry before he installed the plywood. The newly installed plywood was now absorbing the moisture from the concrete raising it to 18 - 20%. Way above the recommended 12%. 

Even with the heat turned on, this situation would take a really long time to correct itself.

The result?  All the plywood had to be removed....an expensive mistake.
Now, with the concrete exposed the heat was turned on and the concrete allowed to dry.  The new 3/4" plywood was then installed. 

At least a bigger disaster was averted...had the hardwood flooring been delivered to the site and allowed to acclimate on the 18% sub-floor, it would have absorbed the excess moisture and been installed in an expanded state. Later, once the heat was turned on, the flooring would have shrunk leaving behind unsightly gaps between the boards.

Simple advice:
  • Just because the concrete is hard and looks dry does not mean that it is dry enough for a hardwood floor installation. Check the concrete moisture content and the moisture content of the 2 x 4 sleepers before you overlay with plywood.
  • Ensure that the home's heating system is operational, the temperature in the home is approximately 20 celsius and humidity levels are between 40% and 60%.
  • If the heating system is not yet hooked up, do not deliver the hardwood floor to site until it is.
  • Under good drying conditions, concrete dries at about 1" per month in a 3" thick pour.  Radiant heated slabs will dry much faster. The thicker the slab the slower it dries (i.e. 4" might take 5 months to dry and so on).

Stain samples on oak flooring
When sanding, staining and finishing a hardwood floor, it is a must that the customer be present on site for the stain approval/sample process. 
If the customer feels they've been part of the colour choosing process, they're more likely to be satisfied with the colour after the job is done even if it is not quite right.  This process also gives the customer and the finisher an opportunity to review the job so far. Customers appreciate this!

People see colour differently.  A colour match for one person may not be a colour match for someone else.  Hardwood changes colour depending on the angle of the light (time of day) in the room and the direction at which you look at the floor.  For a finisher to just go ahead and do a great job matching the colour in his mind is no guarantee of job acceptance later on. The customer's approval should always be obtained.

Some suggestions....
  • Don't rush the process. Set aside an hour to meet on site with the customer and the finisher to review the colour options. This also presents the opportunity to talk about the rest of the job, the schedule, the work done so far and address any concerns the customer may have.
  • Ensure the sample area is prepared in the exact same way as the rest of the floor. If you are 'popping' the grains with water prior to staining then pop the grains for the sample patch too.
  • Have the finisher prepare a small section of flooring in a closet or indiscreet area of the floor where small samples of different stain colours can be applied.
  • Have a form the customer can sign off approval on. The same form should have a space where the finisher can write down the approved stain combination. This pre-printed form could also include useful maintenance instructions which will encourage the customer to keep the form on hand for future reference.

Advise your customer upfront to avoid problems later....

When the floor is freshly stained, it will look rich and deep in colour - almost like it will when the finish coats are applied.  Inform your customer that the freshly applied stain will quickly dry and begin to look pale, dry and not like the colour they chose.  If the customer understands this ahead of time, you'll avoid a stressful moment when the customer phones upset that the colour they chose is not the one that was applied.

Be clear with your customer that they must not walk on unprotected stain - stocking feet will leave foot prints that may show up in the stain after the finish coats are applied.  If they must walk on the unprotected floor, advise them to wear runners, walk carefully and don't twist their feet when they turn.

Carpet hides a multitude of sub-floor sins and so when buying new carpet you mostly don't incur extra costs for sub-floor preparation and leveling.  In the world of hardwood flooring things are very different.

In my experience for the most part, 7 out of 10 sub-floors will need a small to moderate amount of leveling, 3 out of 10 will need a significant amount and occasionally one will be so bad that it becomes cost prohibitive to fix the subfloor and so the choice is made to go back to carpet.

Ignoring the need for sub-floor levelling to save a little money is not a good idea. Remember, once the floor is installed the subfloor cannot be corrected.

The results of laying your new hardwood floor over an uneven sub-floor will be:
  • Excessive movement which can lead to premature failure of the flooring
  • Squeak and creaks
  • Gaps and separation
  • Veneer delamination for engineered flooring
  • Loss of wood flooring manufacturers warranty
The problems that come with an uneven sub-floor become evident once the floor is installed. If you install a floating floor over an uneven surface then you will notice soft spots where the floor dips when walked on.
If you install a glue down floor over high and low areas it can release under stress
Squeaks and creaks can develop when excessive movement is present in the floor. Note: that a small amount of movement is normal and to be expected with a floating floor because the underlay beneath the hardwood is supposed to compress. The problem of movement comes when the hardwood flooring is allowed to bridge two high spots in the sub-floor leaving the floor suspended over a low spot. 
The flooring is not designed to support wait in this way and so is easily pressed down into the low spot when someone walks over it. If the floor deflects more than 1/8" or 3mm this may lead to a problem in the future.

Leveling adds time and money to the whole project. A moderate amount of leveling will take a day or two to complete in a 500 square foot space.  Estimating how many hours of labour and how many bags of concrete leveling mixture will be needed is like asking 'how long is a piece of string'.  Therefore, I always price floor leveling by the man hour plus materials because it is the fair and equitable way for both parties. 
Cosmetic cracks in concrete slabs (as shown in this image) typically  represent high spots in the concrete and are perfectly normal. This picture shows about a 1/8" width crack that is about 6' long. Such cracks don't pose a structural threat unless something is really obviously wrong such as a difference in height between one side of the crack and the other or if there is movement in the concrete or significant width to the crack such 1/4" or more.

High spots in the concrete will typically need to be ground down using a grinder with a diamond tip blade.  Lots of dust is generated so a vacuum attachment should be used with the grinder.  It is still dusty work so hanging plastic and using fans placed in windows to blow dust outside are again a must.

Beware the 1970's +, three or four story, apartment buildings that are wood frame construction with light weight acoustical concrete, poured between floors. These are particularly bad for building settlement.  Over time the building foundations settle and sink slightly and by the time that slight foundation movement transfers to the upper floors it can result in significant floor unevenness.  This unevenness will pose big challenges for the hardwood flooring installation.

Subfloor levelling is equally important for nail down, glue down and floating floor installation methods.

Good luck with you installation.
I always tell my customers that ‘the first scratch is the worst scratch'.

Typically, when customers hear this they kind of sigh and visibly let go of the hope that their hardwood floor was special and would never scratch.....or..... that the scratch might just magically disappear if they rub it hard enough. 

The truth is - hardwood floors do scratch and continue to scratch if not taken care of.  With this said, customers need to see their hardwood floor as a fine wine aging and improving over the years.  A floor that shows signs of having been lived on and with can still be a beautiful thing. 

Here are some suggestions to minimize the issues that may come up regarding scratches.

1. Most importantly, the customers' expectations need to be properly set before they purchase the floor.  Don’t pull any punches on this topic, your client won’t thank you later.

2. Having established that all hardwood floor finishes scratch (pre-finished and site finished), you can begin to advise them on:

     a) how they can best care for their new flooring (click here for maintenance) and,
     b) advise them on a hardwood style or floor character that best suits their needs. Don’t leave them thinking 
         that a harder hardwood such as Brazilian Cherry will solve the scratch problem because it won’t.  Harder
         hardwoods do dent or compress less than their softer counterparts but the finish on top will still scratch.

3. Factory applied finishes are stronger than site applied finishes. Leave site applied, oil modified finishes, such as Polyurethane or Swedish finishes to cure for 48 hours before resuming normal foot traffic. Water-based finishes cure much faster  (24 hours) - but check the product instructions.

4. Aluminum oxide and ceramic finishes are very strong but still scratch.  It is ,however, unlikely that you will wear through these finishes to the wood. Be clear with your customer, set their expectations. Successful warranty claims based on premature wearing of floor finish are VERY rare in hardwood flooring. Read the 25 year warranty small print and help your customer understand why, because it will be you and your customer against the manufacturer should a claim be made later.

5. The darker the wood floor colour the more the scratches will show. Scratches are typically light in colour and therefore show up in strong contrast to a darker background.  Ever owned a black car?  It's no different in the world of hardwood flooring.

6. If your customer has 3 kids, a cat and a dog, then consider a floor with a busy grain that helps disguise inevitable wear and tear such as a plain sawn, natural Red or White Oak, Hickory, or Ash.  Busy grains distract the eye.

7. Maple (stained or natural), Brazilian Cherry, American Walnut or American Cherry are not good durability choices.  The grains in these woods are subtle and not busy like Oak, hence wear and tear and defects show up more. Always point out that American Walnut and American Cherry are softer hardwoods and will dent easily.

8. Recommend a low or satin sheen. This also helps to disguise wear and tear. Glossier finishes only highlight scratches and imperfections.

9. Dust or dry mop regularly. Spot clean sticky spills. Don’t wet mop the floor. Use a Swiffer in a ‘snow plow’ fashion to accumulate dust and grit.  Use a soft head vacuum cleaner.

10. Keep outside shoes off the floor.

11. Felt glides are a must on all furniture legs, even with laminate flooring.

12. New Kitchen appliances will scratch the hardwood flooring. If you have new flooring in the Kitchen and you are having new appliances delivered make sure the delivery people are take care not to drag or push the new fridge, stove or dishwasher across the hardwood floor. If they do they will leave scratch marks in the floor. It happens so often and is not easy to fix.

13. If you hardwood or laminate in your office and have a rolling office chair, use a plastic desk chair mat to protect the hardwood or laminate floor, they only cost around $40 from Staples.

Fixing scratches

If you have set your customers expectations properly then they know that scratches are par for the course with a hardwood floor   What do you do when the customer calls distressed about the first scratch?
Acknowledge the problem and be part of the solution.... this is good customer service.

Here are a few tips....
Surface scratches of this type caused by dirt and grit, poor maintenance, lack of felt glides etc. cannot be fixed locally but they can be fixed by re-coating the hardwood floor.  With a buffer and a 120 grit screen, the existing top coat of finish is carefully abraded and a fresh coat of finish applied over top.  My recommendation is to employ the services of a professional for this type of work and make sure the new finish to be used is compatible and will bond with the old finish before you commit. WARNING: If the re-coat fails then you are into a re-sand, a much bigger deal. Try a test spot first. 

Compression scratch marks from dogs or dragging furniture cannot be fixed by re-coating. You have to sand off the finish and into the wood to eliminate them.  Fixing this sort of wear and tear for the sale of a property or just to freshen up the floor is very common.  Locally sanding out the damage is not recommended as any patch work will show up like a sore thumb.  Either do the whole floor or live with the wear and tear until you can justify doing the whole floor.

Deep scratches or gouges for the most part can be filled with wood filler and then coloured with a Minwax stain stick (available at Home Depot).  This remedy is a good contender for a local repair because the deep scratch or gouge is often pretty ugly and easily improved with some simple attention.  Don't use black felt tips or sharpies on darker floors, the colour shows up purple!!  Always do a test patch in a hidden area first.

Remember, scratches are a fact of life with hardwood flooring. Help your customers understand this before they make a purchase.
You have a concrete subfloor. When considering the choice of floating your hardwood floor or directly gluing it down to the concrete subfloor, the following list of pros and cons should help you make the right choice.
The first thing you should do however is check with your strata if you have one. Quite often there are rules in place that govern the method of hardwood flooring installation.

Lets start with  the floating floor method of installation. 

The term 'floating hardwood floor' refers to the method of installation.  A floating floor rests on underlay and is not fixed to the substrate or subfloor. Essentially, gravity holds the floor down.

Floating floors
1. Less expensive than the glue down alternative due to less installation time and minimal adhesive cost.

2. Easier to install especially for the 'do-it-yourselfer'

3. Quieter for your neighbours below. The two air pockets between the flooring and underlay and between the underlay and the concrete break down sound transference better than when the floor is glued down.

4. A finished floating hardwood deflects or 'gives' sightly when walked on. This makes living on the floor easier on your legs and back.  Don't worry, the movement in the floor is to be expected because the floor rests on a soft underlay however the amount of deflection must not be excessive. 1/8" is acceptable. Your concrete subfloor should be leveled properly by your flooring contractor. More information can be found here.  You should have no sudden drops or ridges in the concrete before you begin installation. Inadequate or poor leveling will leave excessive soft spots which can cause movement in the floor that may lead to breakdown later on.

5. Soundbarrier. There are many sound-rated underlays on the market, each with their own pros and cons.
Look for the IIC rating on the product (Impact Isolation Class). This rating indicates the amount of sound transference through the concrete subfloor to the space below in a test setting.  The higher the IIC number the less sound transference.  Various products on the market offer an IIC of between 60 and 73 and are priced accordingly.  The best value, in my opinion, is about 70.  Most sound rated underlays should cost you less than $1 per square foot.

Glue down floors
1. With this method of installation, the finished floor feels stronger and more solid underfoot. This is because the floor design doesn't allow for movement or slight deflection. 

2. Noise. Imagine the sound of a foot step on a glue down floor to be a 'dull thud' as opposed to a brighter 'clack' sound that comes with the floating floor design. The sound of the floor is generally quieter to live with because less noise is reflected back into the room you are in.

3. Expense. Glue down floors are more labour-intensive to install and the adhesive alone will add $1 plus to your cost.  If a sound barrier is required, then it will need to be glued to the concrete first, adding yet another $1plus per square foot for the adhesive PLUS labour to install.  You can see how the cost quickly adds up.

4. Removing a glue down floor is a tough job. The adhesive is very strong and designed not to let go.

5. Gluing hardwood to a concrete slab on grade requires a special moisture barrier (the grey product to the left of the glue bed in the picture). This will add another $1 plus labour to install, whereas a moisture barrier for floating floors is no more that  $.10  per square foot.

So that covers the basic pros and cons to consider when choosing a floating versus glue-down hardwood floor.

I'd be interested in hearing what your experiences have been with installations.  What were the biggest challenges you ran into?

Squeaks and wood are par the course in the hardwood floor industry especially in older homes.

Occasionally I have come across squeaking floors that have been installed in new or newer homes. If your hardwood is squeaking after installation, contact your supplier, installer or dealer and ask them to inspect the floor.  They will be able to give you a reason as to why and offer a solution.  If you are on your own having installed the floor yourself then here are some methods we have used to stop squeaks depending on your scenario:

  1. Check the expansion gaps.  These are the gaps around the perimeter of your floor.  Check that the flooring isn't rubbing against a wall or a doorjamb?  If so, these tight spots will need to be cut back and freed up by about 1/4 inch to allow for future flooring expansion.
  2. Add some water to a 'waterbased' flooring adhesive and inject it between the flooring joints where possible. The thinner liquid should penetrate the joints and will harden over time. This works well for floating floors.
  3. Use WD40 or Talcom powder to lubricate squeaky joints.
  4. Glue down floors typically squeak if the subfloor is uneven. Low spots in the subfloor allow the hardwood to deflect up and down when walked on which can cause squeaking over time. Drill a small 1/8" hole and inject adhesive or expanding foam into the cavity.  Be careful not to inject too much too quickly as expansion foam will lift the floor up if given a chance.
  5. A few well aimed deck or flooring screws, (first drill a pilot hole) set below the hardwood surface and then plugged / filled, can help but it is a long shot trying to hit exactly the right spot.

In a home renovation always have someone re-screw the subfloor plywood before you begin the hardwood installation. It's inexpensive to do and doesn't take long - 2 inch flooring screws work great.

In 90% of the cases, in my experience, squeaks come from the substrate not the hardwood. Unless you are prepared to expose the subfloor by removing flooring pieces, you'll be lucky to eliminate the squeaks. Joists, plywood and cross blocking all flex and move and it doesn't take much movement to cause noise. Old staircases are a great example of how old wood subjected to repeated traffic over many years will weaken and begin to squeak. You'll need to rebuild the staircase if you really want the noise to go away.

My advice, in most cases, is to live with the noises and this unique character that your older home came with when you bought it.

One Last Note...
Always purchase wood flooring material from a reputable dealer who has had years of positive experience with the wood flooring brand being purchased.  Saving money at an auction or a 'blow out sale' center is a big risk.  Such things as bad product milling, incorrect kiln drying and poor storage will cause the flooring to perform badly once installed.  Avoid engineered hardwood that has an MDF backing the word is that this method of manufacture is prone to squeaking after install.

As always.... good luck with your flooring!
The importance of testing the sub-floor for moisture before your hardwood flooring is delivered to the job site cannot be overstated.

I've seen it time and again where perfectly good flooring is ruined because the homeowner or flooring contractor deliver the wood flooring before ensuring that the installation area is fully dry.

Small amounts of moisture, not detectable by the eye, are enough to cause significant expansion in the new flooring.   Later, when the flooring dries out because of normal house heating, it will shrink leaving unsightly gaps between the boards.
Use a moisture meter.  Rent one if necessary.
  • Plywood should read no more than 12%.
  • New hardwood flooring should read 7 to 8%.
The difference in moisture content between hardwood and plywood should be no more than 4%.

FYI - if you actually test your hand with the same moisture meter, you will get a reading in the high 20's. This gives you an idea of just how little moisture is needed to affect the wood flooring.