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How To Sand a Wooden Floor

How to sand a wooden floor So you want to sand your floor and transform it into a thing of warm and radiant woody beauty?

Well, at the HireFloorSanders we’re here to help and provide you with everything you need in order to make your project a reality.

From professional floor sanding machinery to good quality seals and abrasives, from paint brushes to nail punches, with our friendly advice and instruction, there’s no need to make any mistakes.We’ve provided the following floor sanding guide to help you to realise a professional result from your floor sanding.

However, if you are not sure about your ability to make a good job of your floors, why not let us do it for you? You can avoid from making costly mistakes and benefit from a quality finish by having your floors sanded professionally.

Preparation

Preparation of Floor Before Sanding

Although it’s tempting, don’t take any shortcuts. Good preparation of a wooden floor before sanding can make a huge difference to the cost and quality of the result.

  • After removing carpet, hardboard, gripper strip and tacks, take a nail punch and hammer and punch down ALL nails 2-3mm under the surface of the wood. Counter sink any screw heads.
  • Properly counter sunk nails/screws will make your abrasive last longer.
  • Replace any broken boards with reclaimed wood. Avoid using new wood next to old, it won’t blend in when the floor sanding is finished.
  • Stagger any ugly crosscuts where electricians or plumbers have had original floor up in the past. This leaves a cleaner and more professional finish.
  • Preparing the wood floor in this way will prevent machine damage and allow smoother sanding as well as make abrasive last longer.
WARNING! A poorly prepared floor can damage sanding machinery resulting in a repair bill of hundreds of pounds.
Choosing Abrasive
For sanding wooden floors, we offer a series of 5 different grades (grits) of abrasive.
  • 24 grit
  • 40 grit
  • 60 grit
  • 80 grit
  • 120 grit

Firstly...Choose the abrasive you want to start sanding with. This decision should be based on the condition of the wood. If the wood is uneven and has not been sanded or stripped previously you probably need to start at the coarsest grit abrasive, 24 grit.If the wood is not in too bad condition or has been sanded/stripped previously, starting at 40grit or even 60grit may be an option.Your initial aim should be to make the floor flat and true. If the wood is uneven then you will not get the abrasive to sand the floor evenly.Hint: Use the finest grit possibly at all stages of the process.
Hint: Don’t skimp on abrasive use. Change abrasive regularly to sand efficiently, avoid machine damage and leave a good quality finish.

 
First Cut, Levelling the Wood
Machinery required:
  • Professional Belt Sander
Abrasive recommended:
  • 24 grit
Often when you begin sanding a wooden floor you will find the wood is not flat and true. This will result in uneven sanding and a poor quality finish.In order to get the floor flat and level, you must begin sanding the floor at 15-45 degrees to the grain. This is known as the First Cut.As always with sanding a floor, start on the left and work to your right. This allows the floor to be sanded without leaving any run marks from the machine in the wood. The First Cut The first cut is made at 15-45 degrees as shown below, if the wood is still not true, you may need to ‘Crosshatch’.The Second Cut or Crosshatch‘Crosshatch’ means sanding at 15-45 degrees in the opposite direction, again working left to right.After performing these cuts, you MUST put the sanding marks back in line with the grain in order that you can remove them with the following finer cuts.Got it? Good, now get to it!

 

The Main Sanding of the Floor
Machinery Required:
  • Professional Belt Sander
  • Edging sander
  • Corner Sander
  • Trio Finishing Sander (optional)
Abrasives recommended:
  • 40 grit
  • 60 grit
  • 80 grit
  • 120 grit

Having got the floor sanded true and level with your first cut, you are now in a position to continue with the main bulk of the sanding.Successive cuts will all be aimed at removing the previous cut until the floor is smooth enough to be sealed.You should integrate sanding the edges and corners with sanding the main body of the floor.Recommended sequence of sanding for boarded floors:

 

Sequence Machine Type Grade of Abrasive
Levelling Floor -1st cut
i) 45 degrees and /or crosshatch
ii) Align grain		 Belt sander 24 grit
Edging – 1st cut
i) All edges		 Edging sander 24 grit
Polishing cut – 2nd cut
i) In line with grain		 Belt sander 40 grit
Edging – 2nd cut
i) All edges		 Edging sander 40 grit
Corner sanding – 1st cut
i)Work all corners and/or areas
hard to reach		 Corner sander 60grit
Polishing cut – 3rd cut
i) In line with grain 		Belt sander

80 grit

 
Corner sanding – 2nd cut
i) Work all corners and/or
areas hard to reach		 Corner sander 80 grit
Edging – 3rd cut
i) All edges		 Edging sander 80 grit
Filling – 2 fills
i) 1st fill a little thicker
ii) 2nd fill wetter 		Manually N/A
Corner sanding – 3rd cut
i) Work all corners and/or areas hard to reach		 Corner sander 120 grit
Edging – final cut
i) All edges		 Edging sander 120 grit
Polishing cut – final cut
i) In line with grain		 Belt sander
Trio (optional)		 120 grit
Cleaning
i) Whole floor, thoroughly		 Vacuum N/A
Colouring the Floor
(optional)		 Manually N/A
Sealing – 3 coats
With finishing in between coats		 Manually N/A

Note: this sequence will require adjusting for parquet and specialist floors. For specialist advice please contact the office

Remember: not all floors require a heavy first cut. If the floor is level and true you can move straight into the second cut.

Lining Up the Belt Sander

In order to maximise the life of the abrasive, line up the drum on the floor so that each successive run is offset by about 1/3, meaning that you overlap about a 1/3 of the drum over the area you have just sanded. Remember, work left to right:

Hint: When sanding the floor after the first cut, divide the room into sections of two thirds/one third. Remember: always work left to right.Start sanding in line with the grain in the larger of your sections (as indicated). Having completed the large section of the floor, turn around and work the smaller section of your floor.and then:

Using the Edging Sander

Warning! Never force the edger to cut deeper into the wood. If the edger is not sanding cleaner or efficiently change to fresh abrasive.

Since the big belt sander, used to sand the boards, doesn't reach tight into the edges of the room, you will need to use the edge sander to go around the edges.

The edge sander is a smaller machine that has a fast, spinning disc of abrasive which is guided right into the edges of the floor.

You work with this machine in a similar manner to the belt sander. You will start with 24 grit and work progressively up to 120 grit, removing all marks made by the previous abrasive as you step up a grit.

Hint: you may find it best to work with the belt sander and the edge sanding machine alternatively in order to avoid leaving marks where one or other of the machines has been working. Ie. work with 24 grit on the belt sander, then 24 grit on the edger, then 40 grit on the belt sander and 40 grit on the edger and so on.

Finishing the Floor

After all that, if you still want more (?!) and for a truly professional finish, after cutting the wood with a belt sander, polish the floor with the Trio Sander.