Concrete basement floor - advice? - Page 2 - PeachParts Mercedes-Benz Forum

Hatterasguy · #16 06-07-2009, 10:26 PM

Well thats true, a lot of older homes are well junk, they did some pretty crazy things. My uncle bought one that had what looked like 2x3's for roof joists!

What are the basement walls made out of in this place? Maybe you should jackhammer a section and dig down to the footing to see what you have.

The worst offenders I have seen are on cheaper homes built after WW1. A lot of them suck, can't beleive they have been standing for almost 100 years.

tonkovich · #17 06-07-2009, 11:47 PM

yes, dry-lok will hold out moisture if it is applied directly to the substrate.

might be rebar ? tied into walls, from floor. or not.

sounds like you want an engineer if you are going to chip it out.

maybe the easiest is to pour four inches on top; a pumper would be prudent.

pawoSD · #18 06-08-2009, 12:40 AM

I've found it interesting the wide variety of floors in basements, no matter the age of the building......the house I just moved from recently was built in 1912....but it had 9 foot ceilings and a nice (unfinished) basement....with a perfect smooth concrete floor.....just as good or better than any modern building I've been in...

But I know some people with a house from the 30's and it has the uneven rough cement floor (one room is dirt).........and the ceiling is about 5.5 feet.....guess it all depends on the cost of the house when it was built.

pawoSD · #19 06-08-2009, 12:43 AM

Quote:

Originally Posted by Hatterasguy

Well thats true, a lot of older homes are well junk, they did some pretty crazy things. My uncle bought one that had what looked like 2x3's for roof joists!

What are the basement walls made out of in this place? Maybe you should jackhammer a section and dig down to the footing to see what you have.

The worst offenders I have seen are on cheaper homes built after WW1. A lot of them suck, can't beleive they have been standing for almost 100 years.

No kidding.....my father in law's house has 2x4's for the roof joists!! Spaced probably 2 feet apart.

He knew something was wrong when he was on the roof and was sinking into it!

He said that some of them had split at knots and actually weren't even supporting anymore.....scary stuff in MI, where having a few tons of snow on the roof during a blizzard is not unusual! He sistered up most of them and made it quite a bit stronger....thankfully.

cornblatt · #20 06-08-2009, 01:03 AM

Thanks for all of your comments and ideas! You guys are great!

It's a rental property, which adds a lot of constraints to the decision making process. I should have mentioned this earlier but I didn't think it was important when I made the original post.

Quote:

Originally Posted by t walgamuth

Although its a lot of work I would advise breaking out the old concrete, leveling the earth, putting down visqueen vapor barrier and wire mesh and pouring a new floor. It will add value to the house too.

Quote:

Originally Posted by pawoSD

I'd bust it up and re-pour (myself)....might be icky work, but the smooth nice end result would make it all worth it.

If I lived there myself, then yes - I would definitely be chipping up the floor, digging down another foot (ceilings are currently 6'7"), and pouring a new slab.

But, as a rental, I would never recover the cost of a project like this through rent, and the scope of the project is also limited as I don't want to disrupt my super-nice tenants any more than necessary (in terms of time and mess/destruction). If I was to sell the house, it's likely that it would be torn down to build something new, so anything I do won't really add resale value to the property.

If I had more time/money, this would be the right thing to do though.

Quote:

Originally Posted by MS Fowler

Why not place a wooden floor, ( 5/8" OSB) over a 6 mil poly vapor barrier right over the concrete? You could use 2X4 as joists to let you shil it level if you want. Leave the concrete like it is.

It's actually too lumpy to put plywood on - truly the worst concrete job I've ever seen. The basement ceilings are low as it is (maybe 6'7" to the bottom of the floor joists for the main floor) so I can't go over top with anything thicker than about 3/4"; putting framing underneath to level it would be too thick. The furnace, hot water tank, etc. are also sitting on the existing floor and would be buried if I add anything with substantial thickness.

Quote:

Originally Posted by jt20

dry-loc is one of those sealant /paints.

I will look up the dry-loc product - thanks for the tip. Your matrix-of-strings idea is a good one - I will do that tomorrow night just to get an idea of how bad it really is.

Quote:

Originally Posted by Hatterasguy

What are the basement walls made out of in this place?

The foundation walls are poured concrete as well. The house was built in 1912. I'm not sure if it's true, but I've been told that it was common at that time in this area for them to make the concrete using the sand / silt they obtained from digging the hole for the basement (the house is near a river and once you get down 2' the soil is very sandy). It's not quality concrete by today's standards, but it holds the house up. Neighboring houses have crumbly foundation walls, so I think I got lucky with this one. The concrete on the floor is only about 1" to 1.5" thick (just a skim coat, like you said).

My goal is to turn the basement from a negative feature of the house into a neutral one with minimal expense / time commitment... it just has to be clean looking so that the tenants aren't creeped out by it.

The cost and time restrictions have led me to the idea of topping it with something (e.g. self leveling compound or sand mix as I mentioned in the original post, with a primer/bonding agent applied first to the existing floor), but I'm not sure what the best option is or if there's something else I should consider.

Thank you again for all of your ideas! I have to come up with a plan by the end of next weekend, so if you think of anything else, please let me know.

t walgamuth · #21 06-08-2009, 04:01 AM

Quote:

Originally Posted by Chas H

The house is 95 years old for starters. Who knows how it was constucted.
Have you never heard of a raft foundation. You can do the search.

The only place I have ever seen a raft foundation is in structures 101. In over 30
years
in the business of designing and working with buildings. I have never seen a raft foundation in any type of building, or read about one.

The Imperial Hotel in Tokoyo by Frank Lloyd Wright was built on a raft foundation according to our architectural history class to resist earthquakes, but other than that I have never seen it.

If you would like to post just one example I will eat my words.

In a house that is ninety five years old, its quite likely there is no separate footing. Often if it had a brick or stone foundation they simply leveled the earth and started laying the brick or stone.

In this case its poured concrete and if the floor is not level that would support the idea of no separate footing too. I imagine if its not level it also may have been formed with individual boards instead of plywood. At that age plywood was probably not available in any case.

If there were a separate footing I would expect to see the floor pretty level, since it would follow that the footing was level to start with.

If it were built on a raft foundation, I would also expect to find a level floor too. Since its not level it probably was like my old house which had originally been built with a glorified crawl space and a dirt floor. Concrete was added later, perhaps when folks started having more stuff and needed a dry place to store things.

Getting a thin layer of anything to bond to a crumbling, pitted surface will be tricky at best. The bond will only be as good as what you are bonding to.

There may be some sort of an epoxy like product that will penetrate and bind the existing material and provide a finish. Dampness though may be a problem and prevent the applicatin of any finish type of material.

kerry · #22 06-08-2009, 09:07 AM

Quote:

Originally Posted by cornblatt

It's a rental property, .

In that case, just leave it alone. It's been there for a hundred years and can stay there until you're long gone. If you're worried about what your tenants think of it, lock the basement door and keep them out. I've got rentals with dirt basements.

cmbdiesel · #23 06-08-2009, 09:27 AM

Quote:

Originally Posted by t walgamuth

The only place I have ever seen a raft foundation is in structures 101.

There may be some sort of an epoxy like product that will penetrate and bind the existing material and provide a finish. Dampness though may be a problem and prevent the applicatin of any finish type of material.

Precisely. Especially in Alberta.

I would be tempted to trowel fresh concrete into the 'craters', then a thorough cleaning to remove all dust and dirt. Possibly a wash with muriatic acid, then an epoxy finish.

Chas H · #24 06-08-2009, 09:40 AM

Quote:

Originally Posted by t walgamuth

If you would like to post just one example I will eat my words.

.

I have no way to reduce/scan the plans for a friends building completed about 20 years ago using a raft foundation.
I doubt you have inspected the house being discussed so you have as much idea as me how it was constructed.

jplinville · #25 06-08-2009, 11:15 AM

Skim coat it with enough concrete to give a smooth finish

strelnik · #26 06-08-2009, 12:19 PM

Quote:

Originally Posted by MS Fowler

Why not place a wooden floor, ( 5/8" OSB) over a 6 mil poly vapor barrier right over the concrete? You could use 2X4 as joists to let you shil it level if you want. Leave the concrete like it is.

What about combining the best of two methods?

1. Epoxy paint and a thick (I would go 1") wooden floor.

2. If the basement isn't finshed, how about putting in some leveling strings and pouring 4" of concrete over it, with some steel nails driven in to be 1" above the current surface, to help anchor? You could even do the basement a portion at a time. Makes it less costly in one lump and enables better control. I say this because I have no help for anything, have to do it all myself.

Which is why my house is so dirty...

Skippy · #27 06-08-2009, 12:26 PM

How do your tenants feel about the basement? If they don't like it, you can probably get them to help bust out the old floor for cheap. That may allow you to do a new floor and stay within the budget. Otherwise, I say either skim coat it enough to cover the craters, or just leave it alone.

mgburg · #28 06-08-2009, 01:47 PM

Your one issue is moisture ... to handle that you could break/chisel in two channels running the length of the basement, then at the one end/corner, have them meet at a newly installed sump...install drainage tile/piping, backfill with course gravel, THEN pour in new concrete to seal the channels, finish off the area around the the new sump and bring the whole floor up to level and 4" over the highest rough point...drop a pump into the sump and your basement is now;

#1. level and;

#2. dry enough for tenant storage or cardborad boxes (unless the sump-pump fails).

That would be the minimum I'd do and the value of the property (when you decide to flip it) will be improved...

I do like strelnik's idea of driving some method of surface-to-surface bonding material into the substrate/old concrete to help with the adhesion of the new over the old...the only thing about that is how separated are these "pungy-sticks" and the idea of walking/working around a "nailbed" and not being up on your tetanus shots...ewwwww! But, it might give you an anchor point to tie into to hold the wire down into the new 4" concrete when you pour that in...

Good luck!

Hatterasguy · #29 06-08-2009, 08:02 PM

Quote:

Originally Posted by kerry

In that case, just leave it alone. It's been there for a hundred years and can stay there until you're long gone. If you're worried about what your tenants think of it, lock the basement door and keep them out. I've got rentals with dirt basements.

Oh I didn't see that part. Screw it than don't waste the money.

Only clean it up if you plan on selling it.

TMAllison · #30 06-08-2009, 08:33 PM

I'd go with a topping from someone like Ardex or equalivent. They have products that aren't self leveling too and that are designed for 1" type fills.

Another option would be to speak to your local concrete plant and see what mix designs they have for a 1" topping pour. Bonded, it should work fine if the original is dimensionally stable and free of contaminants. I once did a 3/4" concrete topping over visqueen, over slabs on as well as above grade which was used as a temporary pedestrian traffic surface until I could get some special order slate hand sorted in India to do the job to the silly owners satisfaction. Even though it was an unreinforced, floating topping it was still in reasonable shape 9 mos later when we demo'd it and tiled it.