"Heathcliff" wrote in message
oups.com...
On Jul 11, 2:00 am, "Art" wrote:
We are pulling out a Jacuzzi brand whirlpool and replacing it with a
Sanijet. According to Jacuzzi, they require floor strength of about 55
lbs
per sq feet. Surprisingly, Sanijet wants 100 lbs per sq feet. I am
looking
for ideas on strengthening the floor. I have access from underneath. I
plan on adding an additional piece of sheet rock on top and screwing it
to
the joists. Sistering the joists would probably be difficult because a
portion of the floor is cantilevered but I could put in a bunch of
blocking
between joists underneath the whirlpool if that would help. Any
suggestions
would be appreciated.


Blocking will help some but I think you still have essentially the
whole load on at most half a dozen joists. Vertical support from
below would be better. How free are you to interfere with the space
below? You could put a 4X4 prop under each joist that runs under the
whirlpool, or run a support beam across, perpendicular to (and
beneath) the joists, with a couple of 4X4s or those adjustable steel
jackposts. -- H


Below is a finished basement with a suspended ceiling so vertical support
would be impossible. The only option would be to sister the joists. The
good part is that the jacuzzi will be at the end of the joists which are
short. The jacuzzi is partially located in a cantilevered portion of the
floor. The cantilever and about 10 feet out from it is separately boxed out
from the rest of the joists and joins the rest of the joists with a double
joist parallel to the cantilevered wall.