Top floor cantilever question

Postby **jsr** » June 10th, 2013, 7:32 am

Just wondering what is the maximum lenght a cantilever can be without additional support for a top floor overhang
1 ... Using concrete and steel
2... Using steel beams

Thanks

bluestarz9 · Postby **bluestarz9** » June 10th, 2013, 7:57 am

you know that it would depend on precise dimensions right.

get a professional opinion . this is not the place for this

rdeonarine · Postby **rdeonarine** » June 10th, 2013, 8:00 am

is there going to be any imposed loads on the cantilever or is it only dead load?

Postby **jsr** » June 10th, 2013, 8:22 am

I would be buillding on it

Mr. Red Sleeper · Postby **Mr. Red Sleeper** » June 10th, 2013, 8:52 am

Pay some money and get an engineers advise/ design.

Postby **Ignorant Ignis** » June 10th, 2013, 10:03 am

jsr wrote:I would be buillding on it

non .... and it would be illegal and not pass town and country inspection

Mr. Red Sleeper · Postby **Mr. Red Sleeper** » June 10th, 2013, 10:04 am

^^them doh care abt that.
the mere fact that he's asking this question here proves that he isone of the Trini DIY'ers

Postby **Ignorant Ignis** » June 10th, 2013, 10:09 am

^^^^^ by law it's 4ft for dead load (balcony / gallery)

ppl do what the hell they want anyway and just pay off the inspector

Mr. Red Sleeper · Postby **Mr. Red Sleeper** » June 10th, 2013, 10:16 am

Ignorant Ignis wrote:^^^^^ by law it's 4ft for dead load (balcony / gallery)

ppl do what the hell they want anyway and just pay off the inspector

OPIE!!

Take notes

black start · Postby **black start** » June 10th, 2013, 10:19 am

Opie there are a lot of factors to consider when building a cantilever. My advice would be to get in contact with a civil or mechanical engineer who has experience in this field and seek advice from them.

I think user rory phoulorie may be able to help you out here though....

Also there are a lot of quack engineers out there, so do some research first.

Cool story:
Uncle building his house, hired an engineer to do some design and design calculations for him. Engineer want to build 12'x12' column with 12'' stirrups....many lolz were had on the engineers behalf...

Halfbreed07 · Postby **Halfbreed07** » June 10th, 2013, 11:40 am

question is vague, as cantilevers can be designed to extend beyond it support for various distances.
if you are speaking about a domestic situation, using a 12"X12" RC beam, with a 4"-6" RC slab would give you a 3' extension beyond the support, and that will get approval from T&C.
If you want to go beyond that you will need to prove it with calculations for T&C.
PM if you need further info.

ckavsinba · Postby **ckavsinba** » June 10th, 2013, 12:00 pm

Concrete - 3ft....can squeeze 4 but speak to your contractor as the beams would have to be thicker/stronger

Steel - 4-6ft

Mr. Red Sleeper · Postby **Mr. Red Sleeper** » June 10th, 2013, 2:00 pm

ckavsinba wrote:Concrete - 3ft....can squeeze 4 but speak to your contractor as the beams would have to be thicker/stronger

Steel - 4-6ft

Everyone in this tong is an engineer. When their bldg fall down is level tears after. :roll:

kevin310 · Postby **kevin310** » June 10th, 2013, 4:14 pm

About 4 years ago, I submitted plans with a 4' cantilever and the inspecter told me the drawings had to be revised to show a 10"x10" beam which supports the outer perimeter of the cantilever. These beams would then tie back in and be supported by the columns.

This seems like rel overkill, I never saw any building with that detail

Rory Phoulorie · Postby **Rory Phoulorie** » June 10th, 2013, 4:23 pm

1) What is the intended use of the area to be constructed?
2) What is the proposed spacing for the cantilever beams?
3) What type of flooring is to be installed on the cantilever beam (timber, reinforced concrete, chequered plate, and the like)?
4) What are the details of the member to which the cantilever beams will be connected? If it is structural steel, provide the steel member designation. If it is concrete, provide the dimensions, reinforcing details and 28 day concrete compressive strength (specify cube or cylinder) for the members.
5) What other members are connected to the member(s) to be defined under (4) above?
6) Where is the site located? Proximity to coastline?

You have to be able to answer the above questions to be able to begin to get a sensible answer.

Kindest Regards,

Rory Phoulorie, R.Eng.

trinihub · Postby **trinihub** » June 10th, 2013, 6:26 pm

The 't&T building code specifies 4' as being the max. cantilever length but find it first before you apply it. I'm sure there would be a requirement for floor thickness , re-enforcement etc.

pugboy · Postby **pugboy** » June 10th, 2013, 6:36 pm

many of the truss awnings you see all over the place are diy too
some of them very suspect, more so in the way they are often attached to the vertical