Mosaics, Parquet, Herringbone what ever you want to call them, There's
nothing like the beauty of a block floor, Block floors come in all different
pattens and have been available in all species of soft, hard and exotic
woods throughout the years, many can be found hiding under carpets in
many homes and flats in the UK, Block mosaics require a slightly different
re-finishing process to Floor boards and plank flooring.

Oak Herringbone		Pitch Pine

This guide is for the sole purpose to give the keen DIYer a good chance
of turning something out that will look satifactory. If your looking for
a really good result like the floors you see above and below, please hire
someone to do the job for you. Block floors have been made so much more
easier to do with additional orbital sanding machines and most floor sanders
do not have these machines although they can be hired, If you can lay
your hands on a Lagla trio then you could turn out a good finish, If not
you will need a buffer or at the least an orbital sander but i must stress,
you will not get near the result of that of a Trio or a similar orbital
sanding machine.

Antique Pine		Walnut Five finger mosaic

The Tools listed below are what you will need the Optional tools, you
may or may not need.

Tools You Will Need

10. Pincers (Optional)

11. Filling knife

Safety

3. Steel toe caps (at least when transporting the Floor
sander upstairs)

Preparation

Remove any gripper rods using a pri or Crow bar, be extra careful as
you will find the nails can be really hard to prise out from hardwood,
you may find the block lifting before the nail, lever your pri bar on
the actual block with the nail in your pulling if possible, blocks that
come out will need to be glued back in.

Sweep or vacuum the entire floor, Take a good look over the floor your
about to sand, check for tacks, staples, loose or missing blocks, Glue
down loose blocks and remove staples and tacks as best as you can.

Belt Sanding

Before you start to sand the whole floor do a trial patch firstly try
sanding with an 80 grit, If the floor is flat it may take only an 80 grit
to remove the previous coating and bring the floor back to clean wood,
If the 80 grit is not removing all the finish easily, work back to a 60
grit, If you are still having trouble removing the previous coating go
back to a 50 grit, If it still is not clean after a couple of strokes
you may need to resort to a 36 grit Unless your sanding a really hard
wood such as Wenge or Mahogany, never use less than a 36 grit. For the
sake of this tutorial we will assume i could only cut clean easily with
a 36 grit, If your sanding a 3,4,5,6 or 7 finger mosaic or block overlays
then do not go back anymore than a 50 grit, Finger mosaics are usually
only 9 mm thick and overlay is usually only 10mm. The reason for this
excersise is because you only want to sand the minimal amount as possible
off the floor, remember each sand reduces the life span of the floor,
so the least off the better.

Pitch Pine Block Herringbone		Finger Mosaic

Start with a 36 Grit Sanding belt on the floor sanding machine, If the
floor is has a diagonal patern start sanding at a 45 degree angle (as
above), work forward and backward from right to left one side then again
from the otherside until the whole area is clean, If the blocks run parallel
and across (as above) you can sand from right to left down one side of
the room, turn the machine around and repeat the same process working
from right to left until you reach where you started.

Sanding Herringbone at 45º angle		Douglas Fir

Move up one grit at a time from 36 to 50 to 80 or from 40 to 60 to 80
or from 60 to 80, If you come clean with an 80 then thats all you will
need to do with the belt sander, other than that repeat the belt sanding
stage working from the right hand corner to the left up and down the room
until you reach an 80 grit.

Edge Sanding (Edging)

whatever first grade you used on the belt sander to clean the floor is
what you will need to use on the edges.

If you used 36 start with a 36, 50 start with a 50 or 60 start with a
60 or 80 you start with an 80, Fit the sandpaper disc to your edging machine,
find a point to start from and sand up to the edges, Push along the skirting
board then using a circular motion work back on your self cleaning the
floor into the belt sanders sanded area making sure to smooth out any
drum marks or dips where the drum has not quite been lifted in time, work
clockwise around the room covering about 2 feet at a time until the edge
is sanded clean, you may need to use more than one sandpaper, change as
necessary. The left hand corners that have more unsanded area than the
right will need to be sanded off completely with the edger. Once you have
completed all around the floor and all the edge is clean, repeat the same
process working up the grades and finish on an 80 grit.

You should now only be left with the corners and hard to reach areas
to sand.

Edging with a 36 Grit		Cleaned and Blended

Corners

Use the nose or detail sander or scraper for all hard to reach areas,
any areas not reachable by machine must be sanded by hand.

Sand corners across the grain using a 60 grit sand belt removing the
disc sanding mark made by the edger, then sand with a 60 grit going with
the grain, move on to an 80 grit going with the grain and finish with
a 120 grit by hand, this finishes the corners

Levelling corners across grain		Sanding corners with grain

Orbital

Fit a 50 grit sandpaper to your orbital machine, I'm using a Lagla Trio,
but there are other manufacturers of similar types of machine, If you
have an extra weight to put on, Use it.

You can sand the floor with an orbital starting from any position but
its best to work in sections to make sure you cover every reachable area,
the machine will reach up to about 2 inches from the skirting, with the
50 make sure all scratches in the blocks going accross the grain are smoothed
out before moving on, theses machines will not cause and dips in the floor
unless they are left in one area for a very long time.

Once the whole area has been covered replace the set of 50 grits with
80 grits, repeat the process covering every section reachable. If your
sanding really hard woods you may need to only sand to an 80 grit but
for all soft woods and softer hardwoods such as Oak and teak you are best
to put on a set of 120 grits and close down the grain in the wood and
make the floor really smooth. Never sand higher than a 120 grit using
an orbital as this will cause adhesion problems with your varnish.

Sanding with the trio		Work sections at a time

If you are unable to find an orbital sanding machine you can also use
a buffer with an abrasive fitted to it, start with an 80 grit and finish
on a 120 grit

If you are unable to get on with a buffer you can resort to using your
hand orbital sander, sand out all scratches agross the entire floor area
with a 50, 80 and 120 grit, this is quite a lengthy process but absolutely
worth it, theres nothing worse than horrible belt sander scratches going
across one of these floors.

Step 7

Hand Orbital

The final process is to run around the edges with your hand orbital sander
using 50, 80 and 120 grits smoothing out the couple of inches that the
Trio couldn't quite reach, give the floor a vacuum and your ready to coat
up (Apply the finish)

Palming out with an orbital		Finger block floor ready for varnish

Sealing, varnishing, Lacquer

After a good vacuuming apply varnish to edges with a brush, go across the grain and then with the grain, feather out away from the skirting,		Work at a 45 degree angle for herringbone and simliar patterns and 90 degree for square patterns Use a roller to work in varnish against the angle and then with the angle, leave wet edges to avoid overlaps showing, work across the floor towards your exit.

Above has been worked in at a 45 degree angle Once the first coat is dry, you will notice the surface feels rough (Grain raise, It's worse with some woods than others), Smooth or de-nib with an orbital sander or by hand with a 120 grit sandpaper between coats, remember to vacuum the entire area before applying the next coat.		You may or not need to give a light sand between each coat, I like to lightly 120grit hand sand and vacuum between each coat for that extra smooth finish. 3rd and final coat of varnish should show good build (a fourth coat may be applied for extra added protection.

The Oak floor finished in this varnishing tutorial.		The finished douglas fir floor we was working on throughout the tutorial

Finished Walnut 5 finger mosaic seen unfinished in previous picture (step 7).		American Oak block finished with matt varnish

If you are hardwaxing you will need to apply 2 thin coats on most products,
Read the manufactures recommended application method,

Steer clear of any hardwax products that require a buffing machine,

I have found Osmo the easiest to apply by hand along with Blanchon 'Environment'
waterbourne oil which needs 4 thin coats, applied with a short haired
roller but can be recoated in an hour. Osmo takes upto 12 hours between
coats, the easiest and fastest option is Blanchon 'Environment' waterbourne
hardwax oil.