I have renovated an old train station, which had been moved from its original location and placed on a concrete block foundation. The foot print of the building is 75′ x 25′. When the previous owners moved it, they excavated half of the building with a basement, and the other half was a 3′ crawl space. I am interested in digging out the crawl space side and creating a full height basement.
Any suggestions or advice?
Replies
Why did they only dig out half of the space? Is there ledge in the way? If you need more space it would probably be cheaper and much easier to add on to what you have. Assuming you have room.
Joe,
That is the problem, there is really no space to add on.
Lots of questions.
Is the foundation full height all of the way around... or does it do a typical "step up" at the crawlspace?
Has there been an engineer's study done of the project... both geo and structural?
When the building was moved originally, did they install any steel beam reinforcements... and if so, are they still there?
Is there enough space around the building to effectively utilize beams and cribbing?
What is the structure of the building. It's been moved once... so I am assuming it has integrity to do it. But has there been any improvements that would prohibit the structure from being jacked up? (brick work comes to mind... but there are others)
HVAC, plumbing, etc able to be disconnected without huge issues?
Any foundation in the center of the building? (around jack posts... might be helpful/need extra support in teh center of a building that size)
What renovations have you done already... and are they likely to be ruined with any jacking of the building?
Do you HAVE to have a FULL basement (all the way to the edge of the building... or could you settle with about a 4-5' crawl around the perimeter of the new basement space? (there is a reason for this question... as one project I had an engineer look at had a creative, yet very sound way to excavate the area without jacking the building and involved leaving a crawl around the perimeter and only excavating the center of the space). Detailed explaination would be required... and definately an engineer's signoff for the particular project.
There are many more relevant questions... but this would probably be a good start.
Rich,
In answer to your questions, I'll start with the building.
It is an old train station built in 1876. the structure is wood - 2 x 6 stud walls with 1" wood planks covered with 3/4" board and batten and tongue and groove boards.
The building was moved in 1973, and I believe they did not put a basement in both sides because they did not need it at the time. No steel beams were added, the building was moved on wooden beams.
There is a fireplace in the middle of the building with a large foundation under it. The structure is supported on a 16 x 16 wood beam running down the centre of the building lengthwise, broken only by the fireplace foundation. On the crawl space side, the beam is supported by 4 - posts. One at the fireplace, one at the end wall and two spaced in between.
We completely renovated the rest of the building, including putting in new 2 x 12 floor joists in the end of the building we are looking at now. The foundation does appear to step up at the crawl space end.
There is no engineering study yet, as I have just started exploring the idea. There is room around the building for beams and cribbing, and the services can be disconnected easily.
I would prefer to look at a full basement, however I am open to suggestions regarding the perimeter.
Thanks for your comments and questions. I appreciate the input.
Well, unless you want to re-build that fireplace... I would not jack up the building. It may be possible... but I wouldn't do it.
The project, that I had the engineer look at, has definite issues with jacking the building. Long story.. so I won't go into it.
The solution he came up with was to excavate the center of the crawl... leaving a perimeter that remained as crawl space. He proposed coming off the wall 4' for the excavation... and building a wall to retain the crawl.
Footer under the wall... and re-bar reinforced. The rebar was to be anchored in the footer (which was 48" wide and protruded toward the floor space. He had the rebar running perpendicular to the new wall; bending to 90%; and sticking up into the new wall. He had it speced for 12" block, filled every other cell... and definitely filled in the cells that had re-bar going through it (obviously). But if you have the equipment... pouring the wall would have been a solution also.
We had to run perimeter drain... just as if we were installing a standard foundation (inside and outside of the wall).... and a new sump, as it was too large a space to tie into the existing one.... plus, we couldn't get enough fall to properly drain to the existing drainage system even if we would have wanted to tie in.
The proposal was to also tie the new retaining wall to the existing foundation with a soured slab over the "new crawl"... rebar tying it in in to the wall the same manner as we did with the footer to the block wall (thus you had to plan for the rebar prior to filling the cells).
All of the rebar was to be 3/4"... so we had the dealer planning to bend it per spec (ever try to bend 3/4" rebar? LOL)
We were to excavate around the posts and their footings one at a time.. pouring new post footers at new locations... and putting in new posts. The proposal called for one additional post... as the way we had to do it would have put the posts on different locations... thus obviously different weight loads.
Obviously, every situation is different. But in this particular case... it made more sense to do it this way than jack up the structure. The original foundation remained intact... the dirt around the foundation was supported by an unconsciously overbuilt retaining wall... plus the structure of the walls.. plus the strength of the new crawl being reinforced concrete... well, you get the idea.
We had planned multiple access points to the new crawl.. and several build-ins.
Unfortunately.. the owner pulled out just before we were to begin... so I didn't get to execute the plan. But I was 1000% confident in it.
Disclaimer... as I said, each situation is different. You would need an engineer to develop plans for your particular situation. It may or may not work for your situation.
It's just an idea... maybe something to run past an engineer for a few pennies and a feasibility look-see.
Good luck to ya.
I appreciate your input. I can certainly see the merit in leaving the existing foundations alone. Was 4' a minimum dimension to maintain the integrity of the load bearing area of the existing foundation?
I know what you mean about the 3/4" rebar. We always order our rebar preshaped, as even with the smaller bars, bending is a pain in the ***.
You must have been disappointed not to be able to complete your project. It would have been very satisfying to see it to fruition.
On your advice, I'll run it by the engineer we deal with.
Thanks,
That's just the dimension that was recommended by the engineer... have no idea how he arrived at that number. If I had to guess... it would be a combination of the pressures, the type of soils, the structure, etc.
And yes... I would have loved to have done that job. Oh Well !
I've seen setups where a conveyor type belt is in place, and all the dirt and debris are uploaded out to a cart. A long process in some cases as the old "pick and shovel" method is the only way to remove the materials.
Renaissance Restorations
Antique & Victorian Home Restoration Services
http://www.renaissancerestorations.com
Look into vacuum excavating equipment. It's a new technology, but it sounds like just the ticket if you can find a big enough unit.
-- J.S.
Any idea who the equipment manufacture is so I can find a dealer?
Here are a few:
http://www.ditchwitch.com/dwcom/Equipment/ProductFullSpecView/10475
http://www.vacmasters.com/
http://www.vacsource.com/
-- J.S.