I’m in the process of a large renovation and have opened the basement to one large room. There is a fairly large slope from walls to drain and I want to level the floors prior to framing and subfloor.
Deepest point is 7″ below highest point. Area is 500 sqft. Estimate 125 cuft (500 sqft x 4″ avg depth)
I’ll crack the floor and raise the drain before levelling.
My question:
Are there any good resources (video, text) on how to setup to level the basement?
Looking for a step-by-step instruction!
Cheers
Van G
Edited 11/22/2008 9:47 am ET by Van_G
Replies
Assuming there is no question about the integrity of the underlying soil,
1. Get out your Yellow Pages.
2. Flip to "concrete leveling".
3. Pick out a guy that does "mudjacking". Ok, Pick three. Get bids from all.
4. Pick the guy that makes you feel the best.
Ain't no way you're gonna come close to his price and the little time spent will flabbergast you.
Want to attempt to do the job myself. I figured I would be charged $1000 for the basement and garage and it's about 6 hours work.I've already figured out to get my floor height by simply cutting a 2x4 to length and hold it to the floor joints to get my height.Van G
Van,I'm confused..... are you planning on pouring concrete over existing slab??Harry
Hey Harry,Correct. I simply want to level the existing slab which has a pretty nasty slope to the drain.We need roughly 4.5 cubic yards to finish the basement on the long side (500 sqft x 4" avg depth).We're planning on doing the same to the garage since the truck is there and cost for extra material in one truck in neglible:Garage is 12 x 20 (will measure) and we need an average depth of 2" = 40 cuft or 1.5 cubic yardsVan G
just checking- does the basement collect water? why is there a floor drain (and such extreme slope?) are you trying to maintain some slope to the re-positioned drain?
k
Floor is the original pour from 1949 and is in great shape other than the slope. Roughly 500sqft and the elevation difference from high to low is 7".All homes here in Toronto require a floor drain which is typically in the mechanical room. I will keep a slight slope to the drain (not moving it) and I'm using the Dri-Core sub floor which helps channel any spills.
I would be leary about pouring a slab on top of a slab. I would bet that the original slab has no reinforcing in it and adding an additional 12000 lbs to it might be the straw that broke the camels back. You might be lucky and nothing will happen or you could end up with a lot of concrete to move. Reminds of when a lady asked me to fix a chunk of her side walk that had settled. Removed the side walk and found 8 more underneath it. Everytime it settled they would pour another one on top.
Van,I did a job a few years ago near Bloor and Jane.House built in the late 1940s. Steep lot. Builder drove piers and constructed a grade level beam. Built 2 story CMU house w walk out basement on the foundation.I renovated the basement, about 800 sq ft.When I met the job, the basement floor was just as you describe yours. I removed the existing slab. I found the fill (like brick sand) had settled at some point in the past. The downspouts and basement drain were connected to the city storm sewer. When the fill settled these clay pipes all disconnected, so that the fill was washing into the storm sewer, and down the grade, toward the Humber. ( This is a steep lot, and remember, this house is on piers)Also, the waste pipe had disconnected at the vent stack and all the waste was just going into a "cesspool" under the slab. On most days, I guess the draft up the vent pipe was enough that the basement did not smell too bad,,,, just a faint odor. In heavy rain, the smell was bad.You may want to consider hammering out your existing slab ( the 7" slope you describe is not original), and see what is going on there. You might be surprised.Also, I don't want to discourage you, but think about having the new slab done by a pro. Good flat work is a job for an experienced crew.Best of luck, Harry
Hey Harry, still working in Toronto? My son is living there .
Rich
I have not worked in town for a couple of years now. It's a pretty good drive in and out for me, and the traffic is bad.The job I mentioned in this thread took the better part of a year. Luckly, the HO would let let me start late and finish late, so I could work around the worst traffic. It's still a drag though.The worst in working in high rises. Their really strict about using the elevators, parking, times/days you can work. Really hard to get used to those conditions, and easy not to charge enough for all the BS.Me, I like client w a 100 acre farm and an empty drive in shed close to the house. Thats heaven.Harry
I was asking because my son wants to emigrate there, we're from NJ. He has been living there for almost a year with his wife who is a student.
I'd like to hear more details about how you corected that situation. sounds like a real mess!
"...and it's about 6 hours work."
You might want to reconsider that figure. I'm guessing beaking the original bed will take that long. Then you have to extend the drain up however many inches (the easy part), get your screeding edges set and, pay for the ready mix. Not to mention if you've never finished large areas of concrete, they'll be pouring and it'll be setting faster than you know what to do with it.
Don't get me wrong, I'm not trying to dispute your capabilities. But I've learned plenty of lessons the hard way, and this sounds like one I personally wouldn't want to learn.
A professional mud-jacker, on the other hand, will make a few cuts and get the floor level if a few sections. I don't know what their average rates are, but if it's around $1000, I'd say its money well spent.
See my work at TedsCarpentry.comBuy Cheap Tools! BuildersTools.net
Please update your profile! Since many issues are dependant on the region in which you work, we look at your profile to see where you are writing from. So at the very least, tell us were you're writing from!
Edited 11/23/2008 3:05 pm by Ted W.
I appreciate the good advice and perhaps this is one of those lines in the job that goes to someone who can do it better and faster.I'm moving a shower and toilet drain in the basement tomorrow so I've got to break open a channel and see what's going on. What should I be looking for in terms of disturbed clay pipes?My friend who is helping with the plumbing is going to come by Wed and fire a camera through the pipes below the slab and see what's what.If I do go the route of pouring a new slab (removing current) how much deeper could I go before having to worry about the existing foundation (under pinning)? Picking up an extra 6" to 12" would be a treat.If the current slab is solid and the plumbing checks out, could I not level the existing as I had planned?
Edited 11/23/2008 3:31 pm ET by Van_G
Wish I could provide more answers, but others here are way more qulified for that. But I assure you, they'll be along shortly.
One thing I can say is that if you want to cut slots for a new drain, rent a demolition saw to cut it. Breaking it with a sledge hammer will take out way more of the slab than you want to. See my work at TedsCarpentry.comBuy Cheap Tools! BuildersTools.net
Please update your profile! Since many issues are dependant on the region in which you work, we look at your profile to see where you are writing from. So at the very least, tell us were you're writing from!
Ted, He's in Toronto, Ontario.Mentioned it in an earlier post.H
That's in my signature, doesn't apply to anybody specific. I updated it to be more general. Thanks for bringing it to my attention. :)
See my work at TedsCarpentry.comBuy Cheap Tools! BuildersTools.net
If you haven't already done so, please update your profile. Since many issues are dependant on the region in which you work, we look at your profile to see where you are writing from.
Edited 11/23/2008 4:47 pm by Ted W.
Look for someone who works with "gypcrete," a concrete that has a large percentage of gypsum in it.
Gypcrete flows a lot more freely, and is exceptionally strong, even in thin sections. The contractor will typically shoot wires into the existing slab, then use a laser level to cut each wire off at the precise level. He'll pump the mix in, level it, and let it set. It's that easy.
What is the "new" use of the basement? If living space, why not level with sleepers and insulate for a warmer floor.
If the pipe camera crew find no problems with the pipes, keep the re-work to a minimum.
I am just waging that leveling with sleepers and insulation will be less than a pour and dricor.
Sleepers?Basement will have an open space with rec room and office. 3 pc bathroom, laundry, and a forth bedroom in the addition (already level).This space will get used a lot.Had a good chat with a local builder and he said that the basements in Leaside were known to have 1/4"/ft slope which would be about right for our gross height difference. Suggested roughing getting the floor nice and clean and levelling with a scratch coat as we had planned.Interested to see what things look like tomorrow when I get into the floor and Wed with the camera.Plan on renting jack hammer to break in certain areas so I can break as I need. Is this not the right route for exposing things?
Concrete is hard and cold. This is why I suggest sleepers (2x8 scribed to fit the floor) attached to the floor and insulated. Covered with 3/4" plywood. Where you are this would keep the floor from being cold.
You say you have a good slab so why break it up? Just check the pipes are still good without cracks and damage.
Edited 11/24/2008 7:16 am ET by USAnigel
Any information on how to go about getting the measurements to scribe the sleepers? Do you simply use a level from the ceiling and cut the 2 x 8 and then shim as required?This seems like a more cost efficient route considering I have to put a subfloor down before carpeting. If the end product is as a good as a poured level floor then I'd like to learn more.
Attach 2x4 pt to the slab in a 16" on ctrs grid. These are you sleepers.
Get a laser level, nothing fancy but self leveling and shots a line.
Measure down from the laser line to the top of the sleepers for the biggest drop. ie 7". use a 2x8 as long as you can get in the basement or half the span which ever works the best.
Shim one end till level and then scribe a line following the floor. Cut on this line and install to the sleeper. Your making a long wedge.
Move over 16" and same again until the floor has a grid of 2x10 cut to size. Insulate and cover with plywood.
Added note: Some people add plastic sheet to the top of the sleepers before the leveler pieces. This is to reduce dampness.
Hey Leaside is fairly posh/exspensive neighbourhood in TO.
Lets blue sky this a bit.
How about build up very low areas with 2" (or whatever) lifts of xps styro to get roughly level, add 6x6 re-inforcing grid, install 1/2" pex, pour 2 lifts 3/4" gypcrete and presto, done.
Ahhh... warm, comfortable, wonderful radiant heat.
Leaside was posh... until we moved in :)Had a good chat with a trade that I used on our spec build and he brought up 2 good points:1. it will take 2, maybe 3 days to get the subfloor in via sleeper method and it won't be 100% (floor is that wonky).2. it will take the same volume to level the floor as it will to pour new at 3" thick.We took a sledge close to the wall to see what the footing looked like: we can take out the current slab and pour a new level slab and pick-up 4" in headroom!This seems like the solution. Break the new slab and scrape down a little, inspect/replace/make changes to plumbing, pour new floor.He also mentioned doing hydronic heating in the new floor?
New floor is certainly best bet.
Gain 4". That worries me without seeing it but I will accept what you are seeing.
Certainly a great time to inspect/improve plumbing.
Radiant is awesome. Beyond awesome. CAVEAT. If done properly!!!!!!!!!!!!!
2" minimum xps styro. No substitutes. Did I say no substitutes.
Do you presently have hot water heat?
I have done some work in Leaside. Great neighbourhood.
Did some reading on slab-on-grade hydronic and for 580 sqft it's just isn't in the cards for our budget. Would be great but I'll settle for new level slab and then install dimple membrane (DeltaFL, SuperSeal, ....) and then 3/4" T&G OSB. Carpet will be going on top except in the washroom and laundry (electric radiant).Quick question regarding basement walls:Going to fill a couple of the cracks with type S. Once wall is cleaned up, should I paint?Also, I was going to spray foam the exterior basement walls (interior of the outside walls, it's a semi). For comparison, what traditional insulation cost vs. spray foam at $2.50/sqft for 2 lb closed cell?
Edited 11/24/2008 9:46 pm ET by Van_G
At least insulate properly under slab. Energy efficiency is green:)
For that matter pex is cheap and if you change your mind the proper connections can be made.
Read somewhere else that friends do not let friends pour concrete without pex;)
Seriously, poured concrete is done once and cool/cold floors are forever and a c-note in extra material buys you an option for the future.
Cool dank basements are horrible and do not need to be a fact of life for the troglodytes among us.
Forget the dimple membrane and osb (can you say offgassing).
6 Mil poly under the styro, lay carpet on the slab with pad. Keep the moisture out of the slab from the beginning. You know that concrete is hydroscopic don't you?
What did you say you have for heat now?
We're putting in a new forced air gas (Goodman 75K BTU) and Rinai 75 Tankless hot water heater.What material should I lay on the ground before pouring?$100 in pex for 580 sqft slab - I'm interested.Was my reading correct on the cost of a hydronic system?:$1000 for insulation blanket that goes on gravel (I'm not putting gravel down)$1000 for a qualified mechanical contractor to design a loop, install and pressure test system.Use 6x6 wire mesh on top of blanket to help tie down the tubing for pouring concrete ($500)manifold (?), heat exchanger (?), pump (?)
Too bad about the FA :)
Is FA original to house?
No gravel for drainage? :( Even more important to isolate slab from ground with good insulation and VB
No insulation blankets!! Must be 2" xps Styro. Nothing alse meet NRC tests for R-value under slabs. $ 1.50/ ft
Pex roughly $ 0.50/ft
Yes for mech contractor for system design, tubing layout can be DIY, do not exceed 300 ft loops. Done a bunch without pressure testing now. Pex pretty robust.
That seems expensive for the sheets of wire mesh.
Of course it all adds up, but what price your comfort?
Do you want a heating system or do you want comfort?
Extensive use of the space might be worth the price.
Did you mention electrical mats for some floor heating? Not like hydro is getting any cheaper. :)
High value neighbourhood like yours should help justify the price.
Things are looking good. I've got my crew lined up for the breaking party this saturday - 2 jack hammer's, shovels, wheel barrels, and conveyor are all booked.My eyes are sore from the amount of reading I've been doing on hydronic. We are going to lay 1/2" ThermaPex on top of our XPS inusulation.2 runs of 250' for roughly 520 sqft. I'm thinking 6" centres along the walls for first 3 runs, and then 12" centres for the rest (using 6x6 WWM).Couple quick questions:
- do I need to seat the mesh and pex on brick to elevate or will the finishers just pull it up as they pour?- what do you think of the spacing? I've read 9" along the perimeter and then 16" in the centre? 500' enough?- I assume I can eliminate the electric radiant system in the basement bathroom.- there is an addition on this house (incl basement) that has a nice slab already. If I want to include radiant in this room (140 sqft) should I simply run radiant and pour 2" on top? Or do I need to break this perfect slab and pour as well?- if I do break this slab there is a transition over the old footing (8" step), do I angle the pex through the space and pour the new step over it, or should I use elbows to make the turn?Very excited. Thanks again for all the reply's to date.PS: on the new pour which will be insulated below, I assume I won't need a subfloor on top of the slab before laying carpet?
Edited 11/27/2008 4:41 pm ET by Van_G
Wow, you have been busy.
On the thermopex just be sure it has an oxygen barrier. Critical!!
I would lay 6 mil poly under the insulation especially if no gravel is going in.
6" centres around perimeter and in bathrooms.
9" and 12" as you approach center. Buy a box with a thousand feet in it and be generous, and of course do not exceed the 250'. This is all about COMFORTABLE heat after all.
Theoretically tubing is better elevated or on chairs or pulled up as poured, but not critical. Plenty of foam staple down jobs out there that function just fine. More of a response thing than anything else.
Again, on spacing the tubing a little to much is wayyy better than not enough. Ultimately lower boiler supply temps and less likelihood of striping. You mention carpeting for finish which is fine, but if you or better half picked Elte's fine wool carpets the heat will have to push a little harder.
Yes , eliminate electric radiant. That is a grand right there. The pex tubing encased in concrete will probably last forever, who knows, but the resistance radiant can fail and then it is abandon it or tear up the floor.
On the addition you have a dilemma. Presumably there is no insulation under the new slab. This means you have to create a thermal break with some insulation (again 2" is best) and pour over that. There are other products, quick trac etc that may be better suited. Without seeing it and not knowing the quality and quantity of your help I would consider busting it all up and starting fresh. Probably makes future control of system easier if all emitters are similar.
Just bend the pex to the required radius, no elbows required and creating joints to bury in concrete not the best idea.
No need for subloor over concrete but there is a special underlay for carpet over radiant to prevent constipation..
Thanks for the helpful reply. I'm working on the better half trying to get that addition slab cracked and removed but it could be a tough battle. She's a PM for commercial/industrial construction so I can't pull one by her either.... like "Well Sweetie, we started hammering this slab and the crack went all the way across that one!"We'll see!Can anyone suggest a source for a whole box of ThermaPEX in the Toronto area? Would a supplier like Wolseley sell direct to cash account?How far from the wall should I bring my terminations out: 6"
I'll leave 4' above the slab.What equipment do I need to pressure test it and can I rent it?
Edited 11/27/2008 6:46 pm ET by Van_G
Tell her ICI is different from res. Depends on how important comfort of that room is.
I like my termination points up high enough to look at without being on my knees to do work/connections
Supply/return manifold, gauge, compressor.
Wolseley might/should has done in the past.
Wife as PM should be able to get access somehow
Thanks again. Already did the deal with my better half - compromise - we keep original subfloor and hardware on second floor and tack it down from below. Hard to believe the lady in the house is the one holding the budget in check :)
Not sure I'm reading this right?"Again, on spacing the tubing a little to much is wayyy better than not enough. Ultimately lower boiler supply temps and less likelihood of striping."
Sorry.
Less space, more tubing is always better.
Striping is what happens when the tubing is too far apart and thus floor supply temps are too high, most commonly found on bathroom floors with ceramic tile.
12" is generally fine but never more in res. const. It is all about btu/sq.ft. output.
Going to fill a couple of the cracks with type S. Once wall is cleaned up, should I paint?
Didn't see this before. Ever hear of thoroughseal. Good stuff. No paint.
I was going to spray foam the exterior basement walls.
Closed cell foam below grade beats fibreglass any time. Remember hydroscopic!
NRC found that summer A/C use creates conditions that put vapour barrier on the cold side of wall, moisture condenses, runs down to floor and across it. OH MY, my basement leaks. Dig up and waterproof wall and it still leaks OH DXXX!!! Been there, done that, tore out the fibreglass and put in foam. Oh, and do not be using steel studs on exterior walls.
HTH
you could do a mud bed with deck mud...basically 4 0r 5 0r 6 parts sand to 1 part portland...you mix it with just enough water that it stays together, almost like a snowball, then you make little screeds around the perimeter and in the field and then pack it and screed it...you have to tile it after though because it cant take the same wear that concrete can...probably requires more muscle than brains
Since water finds its own level, plug the floor drain, fill the basement to the highest point in the floor and freeze. The floor will be perfect.
Another reference to a Sponge Bob fix, but it will work.
Family.....They're always there when they need you.
When pouring our slab on Tuesday, should I be using the thin poly barrier between the slab and the block?Removing the slab tomorrow, inspecting and making some adjustments to plumbing on Sunday and then poly, XPS, WWM, and PEX on Monday.
Slab is out and basement is dug out. Sore back but worth it. Hopefully we don't get too much snow before Tuesday.Do I need to insulate the side of the slab before we pour?
I would. Heat goes to cold by whatever vector you provide. More 2" xps please.
Think enclosed envelope.
Heat losses are are greatest at the perimeter and the R value of masonry or stone is next to nil.