Removing ceiling ties and purlins
 

hey up! i have a workshop to which i have fitted a car lift...but i now
need to remove the ceiling ties(to which there never was a ceiling fitted),
and the purlins which are half way up the 45degree rafters, in order to be
able to lift the car into the roof space suficently enough to allow standing
room underneath. i know the only way is to suficently strengthen the
rafters so that they dont sag and install collars higher up. but i want them
as high as possible..not just the third of the way up that is recomended.
so my thinking is to strenthen the rafters with u chanel 3 or 4 mm steel
cupping and screwed or bolted to the raters. then using steel strips as the
collars but higher up...say in the top third. has any one any experience of
this method or any comments? all very welcome! (arcitect due to advise
later next week..but would like some feedback on my ideas)

cheers!

steve

In article ,
"r.p.mcmurphy" says...
hey up! i have a workshop to which i have fitted a car lift...but i now
need to remove the ceiling ties(to which there never was a ceiling fitted),
and the purlins which are half way up the 45degree rafters, in order to be
able to lift the car into the roof space suficently enough to allow standing
room underneath. i know the only way is to suficently strengthen the
rafters so that they dont sag and install collars higher up. but i want them
as high as possible..not just the third of the way up that is recomended.
so my thinking is to strenthen the rafters with u chanel 3 or 4 mm steel
cupping and screwed or bolted to the raters. then using steel strips as the
collars but higher up...say in the top third. has any one any experience of
this method or any comments? all very welcome! (arcitect due to advise
later next week..but would like some feedback on my ideas)

I can't help thinking it would be less hassle to dig a shallow pit than
mess around with the roof structure.

"r.p.mcmurphy" wrote in message
...
hey up! i have a workshop to which i have fitted a car lift...but i now
need to remove the ceiling ties(to which there never was a ceiling
fitted),
and the purlins which are half way up the 45degree rafters, in order to be
able to lift the car into the roof space suficently enough to allow
standing
room underneath. i know the only way is to suficently strengthen the
rafters so that they dont sag and install collars higher up. but i want
them
as high as possible..not just the third of the way up that is recomended.
so my thinking is to strenthen the rafters with u chanel 3 or 4 mm steel
cupping and screwed or bolted to the raters. then using steel strips as
the
collars but higher up...say in the top third. has any one any experience
of
this method or any comments? all very welcome! (arcitect due to advise
later next week..but would like some feedback on my ideas)

cheers!

steve



Could you remove the rafters from the above the area you need, and then
build them back square with the wall and roof height. Like a big L but
upside down to match the roof height and the distance out to the wall.

Create a big dormer is what I'm trying to say. :-))

There appears to be nothing to stop you from doing this. If you look at
church roofs from the late 19th century, many of these used straining
rods at high level to prevent the rafters from spreading. I'm sure that
a bit of old style O level maths would let you calculate the forces
involved and let you determine the sizes etc required.

Regards
Capitol

In article , "Capitol"
says...

There appears to be nothing to stop you from doing this. If you look at
church roofs from the late 19th century, many of these used straining
rods at high level to prevent the rafters from spreading. I'm sure that
a bit of old style O level maths would let you calculate the forces
involved and let you determine the sizes etc required.

I expect the rafters and walls were rather more substantial than those
in the OPS garage though. If he's going to follow church architecture
he should build some nice buttresses to support the roof.

In article ,
r.p.mcmurphy wrote:
hey up! i have a workshop to which i have fitted a car lift...but i now
need to remove the ceiling ties(to which there never was a ceiling
fitted), and the purlins which are half way up the 45degree rafters, in
order to be able to lift the car into the roof space suficently enough
to allow standing room underneath. i know the only way is to
suficently strengthen the rafters so that they dont sag and install
collars higher up. but i want them as high as possible..not just the
third of the way up that is recomended. so my thinking is to strenthen
the rafters with u chanel 3 or 4 mm steel cupping and screwed or bolted
to the raters. then using steel strips as the collars but higher
up...say in the top third. has any one any experience of this method
or any comments? all very welcome! (arcitect due to advise later next
week..but would like some feedback on my ideas)

I had similar in my attic conversion, and the existing purlin was replaced
by two steels - postions determined by the size of the exposed sloping
ceiling. Obviously, calculations were done to support this. They are tied
to the rafters.

I'm surprised you're so tight for space that a purlin position matters? In
my case, it was for cosmetic reasons.

--
*Isn't it a bit unnerving that doctors call what they do "practice?"

Dave Plowman London SW
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