hey all! 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
"r.p.mcmurphy" <[email protected]> wrote in message
news:[email protected]...
> hey all! 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
>
>
>
A couple of better forums are alt.home.repair and alt.building.construction.
That said, if you have a stickframed roof with rafters on 16" or 24" centers
(etc..) with ceiling joists (your 'ties'?) and collar ties (your 'purlins'?)
above you can:
1. double or triple the rafters outside the space needed for the lift;
install fullspan ceiling joist members to these rafters with sufficient
mechanical connection to resist the outward forces; install 2X horizontal
framing members (purlins) between the reinforced rafters (keep the o.c. span
to within the limits of the existing roof deck); reattach the roof deck to
the new purlins.
2. alternately install a ridge beam that spans the area you want to open and
hang the intruding rafters from it.
A lot of this is dependant on the spans and loads of your particular
building. Your architect will have a better take on it than I.
"r.p.mcmurphy" <[email protected]> wrote in message
news:[email protected]...
> hey all! 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
>
Steve, You need the advise of a structural engineer. An architect will only
render the site and give it to the engineer anyway.
Dave
"r.p.mcmurphy" <[email protected]> wrote in message
news:[email protected]...
> hey all! 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!
Go with the architect's advice. Why bother getting it otherwise?
--
-Mike-
[email protected]
"r.p.mcmurphy" <[email protected]> wrote in message
news:[email protected]...
> hey all! 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),
Those generally ware not there to hang a ceiling. They hold the walls from
spreading apart as the weight of the roof tries to spread them apart. They
generally run perpendicular to the ridge row.
"TeamCasa" <[email protected]> wrote in message
news:[email protected]...
>
> "r.p.mcmurphy" <[email protected]> wrote in message
> news:[email protected]...
> > hey all! 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
> >
> Steve, You need the advise of a structural engineer. An architect will
only
> render the site and give it to the engineer anyway.
>
Depends. For something simple like this an architect can do the calcs and
stamp the drawings. That is as long as they are not clueless.
-J