The Florida agriculturist. [volume] (DeLand, Fla.) 1878-1911, 1882-10-25
Coal Tar not Beneficial to Shin

giles.
The Husba3.anlan.
A Pennsylvania correspondent in.
quired of the Eimira IN. Y. Farm
er's Club:
81 would like the advice of the
Club about painting a single roof
with coal tar. Will it preserve the
shingles enough longer to pay the
cost? The root is hemlock shingles.
Is there anything else better than
coal tar and not so lve?"
A member whose observations of
the use of coal tar on shingles were
made years ago, expressed in strong
terms condemnation of the practice.
His father conceived the idea of saw
ing the roof OF a mill through the
preserving influence of coal tar, so he
applied it to the shingles after they
were partly worn, and the effect was
to hasten decay at the point where
the overlapping courses dropped wa
ter on the courses below. The moist
ure appeared to be held with the .ef
feet of rotting the wood in short
time, while the coated butts remained
sound. He believed that the OBJ
ject might have been accomplished
by dipping the shingles in hot coal
tar before laying them, belief sus
tanned by the fact that processes of
decay seemed TO have been arrested
on the portion covered. But be sug
gested as a better way soaking the
shingles in a strong, no: lime wash
before laying. The one fact otex-
IRENE importance which he regarded
as fully demonstrated was, that coal
tar spread on shingles already laid
hastens decay by retardlng the flow
at the very point where 1t should he
free-that is the point of tapping.
Rotting there is at once destruction,
no matter how well preserved the
butts may be, hence his conclusion
that coal tar is worse than useless
when spread on shingles already laid.
Another objection, urged by a
member who had knowledge OF the
practice, was the offensive dripping
of the tar. In one case dripping had
not wholly ceased years after the APP
plication was made. Of course this
objection applies to the use of coal tar
on shingles before laying. While it
may preserve the wood it brings an
evil that is an effectual offset against
any and every supposed advantage.
The general conclusions were that
coal tar, or paint applied to shingles
already laid has no beneficial effect,
inasmuch as the application cannot be
complete, and parts lett unprotected
have accelerated decay through the
retention Of moisture induced by the
application; that coal tar is objection
able, even when used before the
shingles are laid, because OF the Of
fensive dripping; that shingles soak
ed in lime wash, or strong solution
of lime are likely to have increased
durability through the irnpermeability
of the wood effected by the harden-
ing OF the fibre and the closing Of
pores and that worn single roofs
cannot be restored by any. paint,
wash, or coating.
The inquiry was made: What side
of cut shingles should be laid up?
On this question diversity of opin-
ion had been reported, but there was
entire agreement in the answers made
by. those who had given the mat
ter attention-that the checked side
should be exposed, leaving the un-
broken surface below to escape wear,
for if above the shiDgle is useless the
moment the THU unbroken face is
worn through.
Trough on Rats.o
C1ners ont ratS Toica rOoo1,ao G;oe