Need Assistance for my New House

[ausraja]

Friends,

I am building a new house and have obtained a lot of info from this website.I thank all of you for the very needful information and am willing to contribute for future reference from individuals like myself.I am starting construction on the coming Monday and have the plan and structures ready for the 30*40 site.I am planning to build G+3 Floors for self and rental purpose.

I am attaching my ground floor plan which also has the placement for the 12 columns (9" by 18') for brick construction which will have Concrete - M20 and Steel 8 vertical bars of dia 16mm and 2Leg 8mm diaties at 6" c/c.

The first help that i Need is to want to know whether the Concrete and steel that my engineer is recommending is sufficient to what anyone of you may be using in their constructions?

thanks for your help in advance
Ausraja

[KVS Setty]

Hello,

I am not an expert in civil construction , this is just what i learnt from construction of my house which is still going on and long way to go,just finished roofing of ground floor today.

Concrete grade is ok M20, this is what every one uses for residential houses ,but ensure that they mix it in correct ratio 1:1.5:2 (cement:sand: aggregate).

As for as steel is concerned, it is always better to get it designed by structural engineer and ask him to take a safety factor of minimum 2.(this I learnt from my Architect) and minimum steel consumption should be around 3.5 kg /Sft of construction for a G+3 floors. Again let me remind you I am not an expert in this. All this info is from my readings on net and some docs.

wish you many happy construction days ahead.

[ausraja]

Dear Setty , Thx for you reply.

If not as a structural engineer i was interested to know what are the diameter of steel that others in the forum would be using for thier construction on a 30*40 site for G+2 or G+3 floors.

regards

[ausraja]

Dear all,

In addition to the clarification sought on dia of steel i also had a generic question.

As you know i am building on a 30*40 site.The offset that i am leaving on both side is just 2" and in the front of the site i am having column from the beginning of the site(ie next to the drain). The drawing provided from the structural engineer is to have a footing of 5*5*5 feet and this means to have the column in the center of the footing i have to dig the neighbors land and the drain and if i don't want to do that the column will not be @ the center of the footing.

I believe this problem would be faced from lot of you and want to know is it okay to have the columns to be not in the center of the footing ?

thx for sharing your experiences

[sahu.mgse]

Dear ausraja,
First you should have discussed this problem with your structure engineer seriously. because any solution we discuss here is not of any use unless he/she agrees for that.
In future when you bring structure engineer for inspection he should not object for this.

nevertheless, i had similar problem and with discussion with structure engineer and contractor we had solution:- you may have to interlink links all the front column at foundation stage and footing design (steel reinforcement) for front columns will be different.

you can discuss with engineer above points and decide about the same.

sahu

[sreekbda]

Tell your structural engineer what all columns touch the site boundary wall. They will give an alternate design for the footing of such columns. In that design, the entire footing will fall inside your site only. Steel details for this alternate design will be different.

Extending footing into your neighbouring site is illegal. Don't even think about it!

[ausraja]

I contacted my structural engineer today and he feels its a common problem in a place like bangalore where people dont leave enough offsets for their site.The suggstion that he provided was to use the same specifications steel and to have the footing only in my boundary of my site and drain.The only difference will be that the vertical columns in such locations will be at the edge of the footing and not in the center also the legs of such vertical colmns will not be spread in all directions of the footing.

I enquired two structural engineers and two people whobuilt their houses rescently and they said the same happened to them so not sure what more can i do.

[sahu.mgse]

I contacted my structural engineer today and he feels its a common problem in a place like bangalore where people dont leave enough offsets for their site.The suggstion that he provided was to use the same specifications steel and to have the footing only in my boundary of my site and drain.The only difference will be that the vertical columns in such locations will be at the edge of the footing and not in the center also the legs of such vertical colmns will not be spread in all directions of the footing.

I enquired two structural engineers and two people whobuilt their houses rescently and they said the same happened to them so not sure what more can i do.

The attachment is for footing understanding where column is eccentric.

[ausraja]

sahu thanks a lot and this is a eye opener for all future readers on this forumn.

My structural engineer is an ex employee of a very reputed construction company in Bangalore and has switched to consultancy from last 3 years along with this i had also consulted an engineer in electronic city who have given me wrong information.may be deliberately or they are just fraud engineers who just passed their engineering with 35 marks.

My contractor who was arguing with me till yesterday that i am worrying for no reason turned back to me today saying that he has an answer to my problem and its to tie both the eccentric and non eccentric columns with a beam ....

what is bad is that this engineers have taken 15K for structural drawings and people have built 2 to 4 stories already.I cant blame the contractors because we know they are just experienced people with no rationale behind their talks.

[Manjunath711]

ausraja, there was no need to put an strap beam to the eccentric footing, The strap beam is used in case of Strap footing or in case wherein two columns needs to be combined.