Forming your own basement walls

[Alasdair]

OK so we just got quotes for getting our basement walls formed and poured and we just can't afford it. So I'm seriously considering doing it myself with help from neighbours. I have been scouring the internet and using the George Nash book as reference (he gives details how to build your own forms.) It seems like a bit of work but definitely doable. I'm going to head into town and get some prices for ties, panels etc. so I can crunch some more numbers and work out if it's worth it or if we just have to wait until we can put some more in the bank.

I already found some useful info and pictures:
http://countryplans.com/smf/index.php?topic=2418.0

http://www.servicemagic.com/article.show.Designing-Concrete-Basement-Walls.13696.html

http://www.littlegiantformties.com/index.htm

http://daveosborne.com/dave/articles/foundation.php

And Video:
http://www.youtube.com/watch?v=IQhVtlr_zcY

The footing is already formed http://countryplans.com/smf/index.php?topic=8972.0
The back wall will be 8ft stepping down to a 4ft frost wall at the front. On the 20ft side I plan 8ft wall running for 4ft then 6ft wall for 6ft then 4ft wall for 10ft going down the steps. This will roughly follow grade.

I am throwing around a few ideas which may reduce costs. Two initial thoughts are:

Pouring the basement in two sections tied together with a vertical keyway/rebar. This would mean only buying and building half the forms at one go and the same forms could then be used twice.

Making the forms from doubled 3/8" sheathing ply. I understand that 3/4" ply is standard and that this could be recycled as subfloor but what's to stop you you doubling 3/8" ply (maybe screwing the sheets together) then reinforcing it with 2x4s and your walers? Half the ply would be clean and it could all be recycled in your wall sheathing. (I still havn't priced the two different thicknesses to see if 3/4" is more than twice the price of 3/8" but the looks of horror and hushed tones that the mention of 3/4" ply produce suggest that it might be!)
Another idea using this method might be to stagger the 3/8" sheets to provide more support (this would mean getting your holes for snap ties dead on.)

I would like to hear the views, advice and experiences of other owner builders (and contractors) who have formed and poured their own walls.

Obviously we want to strike a healthy balance between best practice and what is most cost effective for us.

[firefox]

If you are mixing your own concrete on site you might consider
using a slip form concept. Make a form as though you were only
making a low wall. In addition to the snap ties, have some threaded rod
located at the top of the form. After each pour, you unbolt the form rom the threaded rod, remove the snap ties, then shift the forms up verticaly and push them on to the threaded rod at the bottom and secure with washers and nuts. Repeat the process each time placing some threaded rod at the top of the form for the next course of concrete. Be sure to prep the top of each course properly for the next course so that you don't have leak or weak joint problems.
ie: rough up the surface before it sets and add neat cement and
water on top just before pouring so you get a good bond.
Hope this helps.
Others, please chime in with corrections/additions if need be.
Bruce

[HomeschoolMom]

Speaking of slip form, I thought these looked really nice:  http://www.builditsolar.com/Projects/SolarHomes/Doug/SlipForm.htm  and if I were in an area with a lot of rock piles, I might consider this method.

[MushCreek]

Two layers of 3/8" plywood isn't as stiff as a single layer of 3/4", unless you glue them together.

[rocking23nf]

My concern would be, if you do make a mistake, or something is out, the whole house is gonna be out. Also concrete is messy and dirty. The effort needed to mix enough for basement walls would be huge. I mean that would be 100s and 100s of bags of concrete. Each bag wieghing around 40 lbs or more. Thats brutal work.

[archimedes]

What about dry stacking concrete blocks with surface bonding cement and filling the blocks with rebar and mortar?  Seems more DIY friendly.

[davidj]

What about dry stacking concrete blocks with surface bonding cement and filling the blocks with rebar and mortar?  Seems more DIY friendly.

Or just regular "speed block" (or H-blocK) CMUs.  I did 100' x 4' of this for our crawl space having never done any masonary before and it wasn't too bad at all.  It's definitely easier than regular blocks - mortaring the ends of regular blocks is fiddly if you don't know what you are doing or your mud isn't just right.  It only works if you are gonna fully-fill it, though, as it's not as strong as regular blocks without grout/rebar and it probably gets more difficult if you have lots of openings.  It's pretty cheap, too - no forms and the blocks aren't expensive.

[Alasdair]

Thanks all for your prompt replys, 

I love the idea of slip forming but I have mixed a little bit of concrete in the past and am not particularly keen to do a great deal more! Since I can get a truck in where I am I fully intend to! The time saved alone is worth the extra cost.
We have already ruled out blocks as they are much weaker laterally than a poured wall and here in Nova Scotia we would (supposedly) have to hire a mason to set them! I have seen several problem basements since I came to Canada and they have usually been stone or block! Not to say that is necessarily the case but I think if you have the option you would be daft not to go with the poured wall.
We have stamped drawings for the poured wall and as it is the local norm and the inspector gets to stay in his comfort zone that's what we intend to do.

Mushcreek - True, the two thinner sheets are not as stiff as the single sheet. I wonder what it would require to make it stiff enough for the job. The problem with the 3/4 or 1" ply is that it is not as easily recycled into the house. It could be used as subflooring but that would mean routing the sides with a tongue and groove (which is required by code here.)
We will have a final check to get things square and level as we plan to make the basement ceiling using a post and beam method,
(detailed here-http://www.finehomebuilding.com/how-to/articles/building-a-timbered-ceiling.aspx?nterms=61672,62936&ac=ts&ra=fp)
which will have a thick wooden ring beam around the top of the walls which will allow us to jig thing around a little if necessary.

I'm also going to look into renting forms and see what kind of saving that might make us.
Al

[glenn kangiser]

Harbor Freight has good stingers (concrete vibrators) relatively inexpensively, Al.

Check this out too Al.  http://countryplans.com/smf/index.php?topic=2041.msg32360#msg32360

Somewhere in there are Rapiform clips which could be of use to you - just drill a 1/4 hole and drive 3 hails into the hole in the clip and into the concrete - to position it and hold the bottom of both inside and outside forms - you leave them in the concrete when done.  # nails driven at once into a 1/4 inch hole - a good cheap temp connector for other parts of the job also.  You can do it, Al.... I know you can.

If there is anything I can help with let me know - PM me if I don't reply right away - working out quite a bit yet.

[JRR]

I have done block foundations and walls ... always adding surface bonding cement for additional strength and appearance.  I have done a bit of slip forming. 

What I  have not done is build my own wall forms and poured premix concrete into them ... I don't think my heart would take it.  One break-out of the form and more than your day is ruined.  For me, if I want poured walls (for whatever reason) ... it will be one of the few times I "contract it out".  After all, those guys already have the equipment, tools, and skill sets.  I would expect a bit of contractor-shopping may find a price/cost that is better for you.

[Alasdair]

JRR - I can certainly understand why many people would shy away from pouring walls - the risk/cost of a blow out and the potential time and effort wasted. I must be particularly ornery - it just makes me want to do it more! Lol. 
One of my neighbours has poured a few walls and poured his own basement so I have at least one experienced guy on side. I have helped batch and polish a bit of concrete and poured a few footings for block strip fouundations etc. So I have a fair idea of what I'm getting myself into.
I've rung all the local contractors for quotes and even the cheapest ones are still more than we can afford at present.
So we will be doing it ourselves. The question now is what is the most cost effective way to go about it!
I'm waiting to hear from one local company that rents forms and that will tell me whether we rent or build our own.
I'm undecided yet about which form ties to use - the only type available at my local building suppliers are flat snap ties which fit steel walers. The building suppliers don't stock cylindrical ties, wedges or the walers as all the local contractors have their own. I'm checking out a few other options online at the moment.
Glenn thanks for the info and the great pics! That is one able basement wall! I don't think we need quite that much rebar over here - must be required for earthquake zones I guess. I was considering this smaller stinger - got good reviews and is even cheaper.
http://www.northerntool.com/shop/tools/product_17783_17783
It would have paid for itself (compared to hiring) after only two uses. my only concern might be reaching the bottom of the 8ft wall form but if it's poured a bit at a time I reckon it could be done.

I like the look of those rapiform clips too. I'm checking out a couple of suppliers in the maritaime provinces that may carry some of these items.

[jbos333]

Just chiming in here - I just got a quote for a 24x40 8 foot poured footers/walls with one 40 foot side as a walkout. It was $8500.00. I thought that was pretty reasonable. I'm not sure what the actual concrete cost is, but I'm not sure I would attempt this unless I was saving a very large portion of the job.

Just my .02.......I say go for it if you are saving a ton of money, and have the time and help to get er done!

[Alasdair]

Jbos333,
I thought our quotes were pretty reasonable too. They came in around $7000 for the 20x30 daylight basement. Not much in the big scheme of things but more than we have just now. I reckon I can do it myself for less than half that.
I think we will likely be using this system - it seems to be the standard around here.
http://www.ledrewmfg.com/index_set.html
Thanks for the encouragement. 
Al

[jbos333]

I might just check that system out, Al. I'm all for saving money, but I have learned through trial and error to "choose my battles". I haven't broken ground yet though, so it's not too late. In my case, though, my basement is probably gonna be the only floor (berm home). I am considering, however, the cost difference in framing a "first floor" anyway and just leaving it unfinished for now. Looks like about a $5000 difference in materials so I'm wondering if that's a smart choice in the long run.

Well, I don't want to hijack your thread any more than I just have! One last thing, have you looked into ICFs if you're gonna DIY? I may look into those myself because I will need to insulate anyway.

[MushCreek]

I'm looking into DIY ICF. A friend of mine built his own place for about $6 a square foot of wall area. It seems to come out a little cheaper than a poured foundation, but it is much better insulated. I'm looking at the TF system, a vertical ICF that requires very little bracing. It looks very DIY friendly.

[Alasdair]

I thought about ICF walls but decided against it for a few reasons. Firstly, I have been told that in Nova Scotia we would again have to hire someone "qualified" to do it for us. Secondly, I have friends in Scotland who have built using ICF and whilst they were ultimately pleased with the results none of them would repeat the performance. Thirdly we want to put a root cellar/cool room/larder in the basement which we don't want to have exterior insulation for obvious reasons. http://www.motherearthnews.com/Do-It-Yourself/2004-12-01/Build-a-Basement-Root-Cellar.aspx
I got quotes for ICF last year and they came in at around 20% more than regular wall although this did not account for the price of the insulation you would have to buy for the regular walls. R20 basement walls are required by code since January here.

[Alasdair]

So we rented forms which we had delivered yesterday and I'm waiting for the rest of the hardwear (rebar, anchor bolts, ties, concrete nails, 2x4s, etc) to be delivered today. We decided to pay a friend and neighbour who has a lot of experience to help us out for a couple of days. If all goes well I hope to pour it on Saturday morning.

Form rental and delivery $1100
Hardwear                    $600
Concrete                     $1500
Wages                        $400

Total                          $3600

Our best quotes were around $7000 so we are saving about half by doing it ourselves. Also the 2x4s etc. will be recycled into the house framing. I will post our progress in the house thread.

http://countryplans.com/smf/index.php?topic=8972.0

[glenn kangiser]

Good for you, Al.  The system looks pretty economical relatively speaking.  Note that the job I linked you to was my first wall pour and I was using rather poor recycled plywood the owner had. Very few problems - no losses and only a few minor bulges - usually around corners - watch and double check them.

[rwanders]

Be gentle when you pour--bring it up in fairly shallow lifts to avoid unbalanced stresses--watch for any signs of form shifting---don't get carried away with a vibrator during the pour--don't let the vibrator beat against the forms---have some extra bracing material handy for any weak areas that develop when you start the pour.