Attached
A large scale solid wood flooring facto ry is to be established in Sri Lanka. On th e planning stage o f this industry it w as found th a t
inform ation on wood properties o f local tim b e rs such as H eve a brasiliensis fo r wood flooring are not availab le. H ence, th e p resent
study has been conducted to g a th e r d a ta on selected w ood properties o f R ubber wood and how th e w ood quality changes w ith
grow th rate o f trees.
Hevea brasiliensis 3S y e a r old tre e s w e re selected fro m th re e size classes: suppressed, co-d o m in an t and d o m in an t. S am p le disks
w ere rem o ved a t top (8 0 % ), m id d le (5 0 % ) an d b rea st h eig h t o f th e log length . Radial variations w e re also studied a t percentage
distances from pith to bark.
W ood quality w as assessed by ring specific gravity. Ring w id th rem a in ed m ore or less constant from pith tow ards b ark w ith slight
decrease tow ards th e bark indicating th e uniform gro w th ra te . H o w e ver no specific varia tion w as observed in ring specific gravity.
This radial variation o f grow th ra te an d specific g ra v ity w as sim ilar in all th ree size classes.
Application o f R ubber wood as solid w ood ele m e n ts fo r floorin g w as e xp e rim en tally assessed by hardness to loads applied to th e
wood and specific gravity. Th e m ea n specific g ra v ity o f suppressed, co-do m inant and do m in an t trees w e re 0 .5 6 4 , 0 .6 2 9 and
0 .6 3 1 respectively indicating th a t th e specific g ra v ity o f R ubber wood lies w ithin th e required stand ard fo r flooring w hich is 0 .5 -
0 .7 5 . In th e hardness te s t, it w as observed th a t all th re e size classes generally show a gradu al increase in hardness fro m pith
tow ards bark. The valu es o f ave ra g e h ardn ess o f suppressed, co d o m in an t and do m in an t tre e s w e re 34 1 kgf, 4 0 5 k g f and 4 3 3
kgf, hence co do m in an t and d o m in a n t tre e s have hardness valu es above 4 0 0 kgf, th e stand ard value fo r w ood floorin g. These
results indicate th a t H evea brasiliensis has w ood properties w hich are w ithin European stand ard and In d ia n stand ard fo r
m anu facture o f w ooden flooring.
