Trench or no trench. That's the question?!

[sjenille4]

I want to build an extension infront my house. My house is a corner lot. The road goes right along the side I intend on doing my extension. My contractor insists that it's a small extention and needs no trench under the foundation as I intend to caste right out till the road anyway. Won't a missing trench eventually cause the walls to crack? He says the road will act as the brace. Is he insane? I don't know, but I have never heard of an extension being built without even a shallow trench somewhere. The extension will form an 'L' around the corner of the house. 30ft long x 15 ft wide on one side. 20ft long x 6ft wide on the other side. A clearance of 15ft still will exist from the new walls to road. This will also be concreted. Any advice? Hire him or the man mad?

[car]

When u say extension, do you mean walls and roof or just a concrete floor?

[De Dragon]

A trench typically is required when you need to stabilize a heavy upper structure. You don't always need a trench however, as my two port garage, which was constructed afterwards had none, and it is very heavy as I cast the top 4 inches thick with a 4 foot wall all around, to put in an entertainment area over the garage.
Now in lieu of a trench, we wrecked the corners, dug to 4 feet, and cast butts which we then installed steel beams on. Then we braced the entire structure, installed the deck pans and poured the concrete.

[sjenille4]

Walls and roof going up, it's gonna be an enclosed room.

[sjenille4]

A trench typically is required when you need to stabilize a heavy upper structure. You don't always need a trench however, as my two port garage, which was constructed afterwards had none, and it is very heavy as I cast the top 4 inches thick with a 4 foot wall all around, to put in an entertainment area over the garage.
Now in lieu of a trench, we wrecked the corners, dug to 4 feet, and cast butts which we then installed steel beams on. Then we braced the entire structure, installed the deck pans and poured the concrete.

Walls and roof goin up on it.

[sjenille4]

When u say extension, do you mean walls and roof or just a concrete floor?

Walls and roof.

[skylinechild]

I want to build an extension infront my house. My house is a corner lot. The road goes right along the side I intend on doing my extension. My contractor insists that it's a small extention and needs no trench under the foundation as I intend to caste right out till the road anyway. Won't a missing trench eventually cause the walls to crack? He says the road will act as the brace. Is he insane? I don't know, but I have never heard of an extension being built without even a shallow trench somewhere. The extension will form an 'L' around the corner of the house. 30ft long x 15 ft wide on one side. 20ft long x 6ft wide on the other side. A clearance of 15ft still will exist from the new walls to road. This will also be concreted. Any advice? Hire him or the man mad?

man mad u need a trench - also dont forget u cannot build on the roadside u need to leave a 5ft from the road edge as a shoulder unless u is indian an u grab every inch of land

/ good luck

[sjenille4]

I want to build an extension infront my house. My house is a corner lot. The road goes right along the side I intend on doing my extension. My contractor insists that it's a small extention and needs no trench under the foundation as I intend to caste right out till the road anyway. Won't a missing trench eventually cause the walls to crack? He says the road will act as the brace. Is he insane? I don't know, but I have never heard of an extension being built without even a shallow trench somewhere. The extension will form an 'L' around the corner of the house. 30ft long x 15 ft wide on one side. 20ft long x 6ft wide on the other side. A clearance of 15ft still will exist from the new walls to road. This will also be concreted. Any advice? Hire him or the man mad?

man mad u need a trench - also dont forget u cannot build on the roadside u need to leave a 5ft from the road edge as a shoulder unless u is indian an u grab every inch of land

/ good luck

Thanks!
Nah the extension will be 15ft from the road. However we are gonna concrete straight out to the road.

[Gladiator]

You should do a trench, tie the steel through the corner posts and to the roof. Build it good and strong... remember we had big earthquake and bret pass through a couple years ago.

[sjenille4]

You should do a trench, tie the steel through the corner posts and to the roof. Build it good and strong... remember we had big earthquake and bret pass through a couple years ago.

Yes and that put tiny cracks in one of my beams.

[matix]

You definitely need a trench, maybe some piling. Depending on soil. Get it done properly once.

[rspann]

You should do a trench, tie the steel through the corner posts and to the roof. Build it good and strong... remember we had big earthquake and bret pass through a couple years ago.

Yes and that put tiny cracks in one of my beams.

The beam that cracked was built by the same builder?

[sjenille4]

You should do a trench, tie the steel through the corner posts and to the roof. Build it good and strong... remember we had big earthquake and bret pass through a couple years ago.

Yes and that put tiny cracks in one of my beams.

The beam that cracked was built by the same builder?

Lol nah. This is an older house 50 yrs +

[hong kong phooey]

if you seen land movement before or you see sinking then you should trench .
i do not know if when he say he not planning to trench he planning to break into your original flooring and tie the steel into that structure but he will have to do it along the entire length of the house . he will also have to tie on the top
if you not going to put a concrete roof or a second story loads of contractors try to save you some money and skip the foundation.
it is very important if you have land movement in your area do not skip the foundation . you will cry after

[Zetski]

I want to build an extension infront my house. My house is a corner lot. The road goes right along the side I intend on doing my extension. My contractor insists that it's a small extention and needs no trench under the foundation as I intend to caste right out till the road anyway. Won't a missing trench eventually cause the walls to crack? He says the road will act as the brace. Is he insane? I don't know, but I have never heard of an extension being built without even a shallow trench somewhere. The extension will form an 'L' around the corner of the house. 30ft long x 15 ft wide on one side. 20ft long x 6ft wide on the other side. A clearance of 15ft still will exist from the new walls to road. This will also be concreted. Any advice? Hire him or the man mad?

he is a mad man.. you need to dig a good trench whenever building a wall because rain will soften up the soil causing the wall to lean.. crack and eventually fall.. dont forget to use steel to reinforce it..

[FordeG]

Trench but also depends on the soil type. Got any bore hole analysis done

[sMASH]

trench for the room part,
if the rest of the concrete out to the road way is on fairlly flat land, and u cast a thick enough slab, u could get away with no trench for that section.

and, fire that builder. that is a mad man. he gone when u hadda fite up with cracking walls,

[sjenille4]

So I ended up changing my contractor. But now that the foundation is done. It seems he left a 40ft wall ( a flats) without any steel rods for posts !! He mentioned about using vertical blocks at the corners and centre of the 40ft wall, along with grey concrete blocks to 'hold' the wall together.
Will my wall fall down. No windows or doors are going on it and a roof will be resting on it as well.

[Rory Phoulorie]

The wall is a load bearing wall.

That load bearing wall should have been built using nothing less than 152mm (6 inch) wide (concrete or clay) blocks. Along the length of the wall, you should have had shear panels, that is, sections of wall of a minimum length (1.8m) where the cores (vertical core blocks) are filled with concrete and reinforcing steel (12mm diameter high tensile rebar at 400mm centre-to centre spacing, or 1x12mm rebar installed in every other core).

At the corners of the wall, the cores (vertical core blocks) should have been filled with concrete, vertical reinforcing steel (3 x 12mm diameter high tensile rebar), as well as stirrups (6mm diameter mild steel at 400mm centres) confining the vertical reinforcing steel).

If this wall intersected other (internal) walls along its length, the cores (vertical core blocks) should have been filled with concrete, vertical reinforcing steel (12mm diameter high tensile rebar), as well as stirrups (6mm diameter mild steel at 400mm centres) confining the vertical reinforcing steel). The cores (vertical cores) of both walls at the intersection point should have been filled with concrete, vertical reinforcing steel (4 x 12mm diameter high tensile rebar), as well as stirrups (6mm diameter mild steel at 400mm centres) confining the vertical reinforcing steel).

So, to basically answer your question, the wall will likely fail during a significant environmental event (extreme wind load or seismic load).

[pugboy]

somebody built a 40ft wall without any columns and calls themselves a contractor