Build Your Own House

Thanks Shane! You must start a thread and tell us all about it

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Simon.

The adventures of an owner-builder in the Tallarook Ranges

I bought one of China's Finest petrol gensets and I reckon the battery fired it maybe 10 times before it died. I charged it once and it lasted another half dozen starts. Similar story to the electric start motor I have on another gadget I built.

We have half a dozen of China's Finest stationary engines around the place from the genset to water pumps and I have to say despite expecting one to fail dismally sooner or later all of them have been hassle free apart from a regular check and oil change.

Well, my rammer earth tamper arrived today from the US - looks like a solid, strong unit. Very happy

All I've got to do now is figure out what fittings and hose to use with it. The eBay listing says the air inlet is 1/4", but my thread gauge says it's either 13 or 14 TPI and 0.8" diameter more or less, and Wikipedia suggests this is more likely to be 1/2" BSP.

Anyone with a tamper, what's yours?

I've also gotta figure out what I need on the compressor, as it's got two 1/4" barb fittings and one large female thread (which I think is the same as on the tamper, gotta measure it). I'm thinking that at 32CFM air consumption, it'll need at least a 1/2" ID hose...

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Simon.

The adventures of an owner-builder in the Tallarook Ranges

Simon,
Nice work on the blockwork, I am pleased to hear that you have the patience to undo things that you are not happy with in order to get them correct. That will certainly pay off in the long run. I feel that I am pretty good at doing that and still I catch myself out with things that I should have sorted long ago. Along the same lines, I have also learnt the benefits of not making rash design changes as 'sleeping on it' usually reveals what the consequences of the change are going to be and you can then decide whether to go ahead with it or not.

As far as stepping the formwork up, I assume that you would be trying to do each full panel in the one day to avoid a dry or cold joint (especially with the reo). I would do 2 sets and then lift the lower set for the little extra bit on the top (as I mentioned in my thread). Instead you could look at making the forms only 600mm high so you can step them up more regularly. Unfortunately I did not attempt to step any of my forms as I made enough for the entire panel so I do not know how the uncured lower part would stand up to having the upper section rammed on top of it. One benefit of the end column system is that some of the load will be taken by the end columns.

I am interested the way you have added vertical elements to the formwork. Are the outside vertical elements only there to hold the small vertical pieces that sit against the ply in place? In think what you have done will only provide additional support to the ply so it does not bow between the walers (and this could happen since your waler spacing is 400mm). I do not think it will help with the waler itself bowing unless the top of each outside vertical piece is tied to the one opposite with a threaded rod (and if you do that you may as well just tie the opposing walers together instead. I assume the horizontal walers are continuous and the vertical pieces against the ply are just blocking. Do the ouside vertical pieces just hold the blocking in place? You will see vertical elements on concrete formwork but they will be tied together with rods at least at the top and bottom as it doesn't matter so much if there are rods in the way for pouring concrete.

I don't want to spoil the adventure of experimenting for yourself but I assume that you are posting your designs so that you can receive feedback. I did not have any bowing of the formwork between the horizontal walers, only bowing of the waler itself. If you wanted to reduce this, I think the best way would be by increasing the width of the waler (in my case from 125x45 to 150x45) or using graded hardwood instead of oregan. Reducing the spacing to less than 300mm would also help. Let me know if I have misunderstood the intention of your design.


My tamper has multiple adapters/reducers connected to it by the previous owner. I will try to identify the thread on the tamper itself (Hopefully it will say in the manual). I will have to get back to you.

I see on the Ingersoll Rand website that their backfill tamper has a 3/8 inch NPT inlet and min 1/2 inch hose. http://www.ingersollrandproducts.com/IS/modelcomp.aspx?am_en=506

Bluey.

Thanks! I will confess to being a bit of a perfectionist with some things, but with this in particular I felt it's pretty important to get it right, given the structural importance of this wall in the project. I'd rather spend a single day now and undo a potential mistake, than have it come back to bite me in the arse later (or worse, be there for me to look at and worry about forever!)



Absolutely, once I start a panel I'm not going to stop until it's finished



Yeah, I've been thinking this myself. Quite aside from the weight of a 1200 high panel, given the wall is only 2520 high I'd probably need at least one 600 high panel for the final lift so it may be more sensible to make them all 600. My reason for leaning towards a bigger form though is that I'd like to avoid the hard visible lines in the wall that seem to be common with smaller panels.



The detail of the walers and form reinforcement are really subject to change, depending on the materials I find at my disposal when I come to build them. I've drawn them all at 90x45 mainly because I'll have plenty of it around, but I've also got a good supply of second hand 150x45 structural pine which I picked up to build the slab forms. Since I've got more slabs to pour I've been aiming not to cut this up any more than necessary.

What I've drawn currently is full-length horizontal walers with infill pieces (screwed & glued) between them vertically, then vertical spars over the top of the whole lot (screwed & glued again) to tie them together and provide a positive mechanism to lock the forms together when they're stacked.



No, not at all - the more feedback, the merrier; positive or negative. The whole point of drawing everything up to the last detail is intended to be a learning exercise - I've certainly discovered a few design shortcomings myself this way, and I'm happy to accept advise from others who've been there already and can spot problems that I may not.

It's interesting that you got very little bowing with just horizontal bracing.. maybe I'm just being paranoid by adding it vertically as well



Since I posted that I've been googling incessantly to try and figure out what is commonly used on these tools. I found a PDF on Michigan Pneumatic's website which has specs, and all of their throttle bodies have a 1/2" NPT inlet thread. Mine measures pretty close to the specs for that thread (13 or 14TPI tapered, 0.850" at the largest end), so I reckon that's what I've got. I'll take the throttle off and pop into Pirtek tomorrow, they should be able to identify it (and supply a barb fitting too).

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Simon.

The adventures of an owner-builder in the Tallarook Ranges

Hi simon
I doubt whether i could maintain a thread on my build , i am finding it difficult enough without any added stresses.
Besides our bog ugly fire shelter home would be pretty boring to most others.
We were supposed to do the slab in january then last tuesday then today but now looks like monday will be a chance..all very frustrating but i hope in the end the wait will be worth it albeit few months behind schedule
anyhow here are a few photos of the formwork...thought they may be of interest

Thanks for posting the pics, Shane. You'd be surprised about the build thread, personally I find it a little cathartic to write about my progress, it helps bleed out any stress (not that I find myself getting all that stressed... yet) and it helps to resolve questions and problems by explaining them to others, even if nobody's reading

Very interesting forms you have there. My original intention was to use steel angle to reinforce mine, but I found the process of building my first prototype too much hard work. I've never been much of a metal worker; I've only started teaching myself to oxy weld this past few months. I've always found timber much easier and satisfying to work with, and it's easier to come across cheap second hand materials than it is steel (or so I've found, anyway).

Have you put those forms to work yet? Do you know how they perform with respect to bowing? It looks like you've used something like liquid nails to attach them (in addition to screws from behind).. ?

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Simon.

The adventures of an owner-builder in the Tallarook Ranges

Quick update: the retaining wall is coming along, but it sure is taking longer than I'd hoped. Four courses complete this weekend, although it's been truncated a bit by the weather.



Six courses down, six more (and a fraction) to go. I'm in two minds with what to do to make up the required 2520mm height when I get that far, on one hand I could diamond-cut the blocks to the required height before core filling, but on the other I'm tempted to set up some formwork to the right level when the cores are filled and "overfill" a concrete beam across the top of the wall. I'm likely to get the height more accurate and consistent that way.

There was a bit of adventure on Friday morning too - the truckie who delivered the steel needed to turn his truck around, and put his nose down the hill off the house site slightly and then didn't have enough traction (being unladen) to reverse back up. So he had to take the truck down the hill a bit to turn around.

Needless to say he couldn't get back up again.

An hour an a half later, a sheet of reo steel under his wheels and much pulling, bogging and cursing with the bobcat and we got him out again... just.

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Simon.

The adventures of an owner-builder in the Tallarook Ranges

Wow, has it really been 8 days since I last updated here? Time flies when you're building a wall!

Short story is I've finally got this wall done. I'm thoroughly sick of lifting and placing these concrete blocks, although I can definitely see how you'd build up quite a physique building with these things day in day out.

A quick pictorial:











It's not the straightest wall in the world - the inconsistent sizing of these concrete blocks makes it difficult to keep a consistent line, and over the full height the wall has grown a little "personality", shall we say?

No big deal, I'll form up for a concrete beam across the top of the wall when we core fill, and that will give me the perfect level for the suspended slab above. For once I'm not going to exert too much pressure on myself either - I'll arrange for an inspection Friday this week, then get the forms installed in preparation for the concrete fill next week. Plenty of time

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Simon.

The adventures of an owner-builder in the Tallarook Ranges

Hi Simon
I built a cellar using these same blocks and had the same issues trying to keep them plumb and straight. I found using a string line and long straight edge to help keep it true. Using a diamond grinding blade on a 5" grinder I'd take the high points off and pack the low points using plastic packers. If I didn't do this you end up compounding the highs and lows.
I'd also recommend doing the core fill in two lifts as any more you risk blowing the sides out of the blocks with the hydraulic pressure of the core fill. The core filling operation often involves putting a u-shaped piece on the end of the concrete pump hose which the operators love to hook onto the top of the block wall but this always moves the blocks so I'd suggest avoid using the u piece and just hold the hose by hand and not resting it on the un-filled wall. Ask for a pump that comes with a remote so the operator has a lot of control over the core fill otherwise it ends up all over the wall, floor etc. 170-200mm slump using 7mm screenings at 20Mpa is a good mix. It needs to be very runny to get into all the voids of the block work.
If you need to waterproof the back of the wall before backfilling you may need to consider filling the joins with a grout to give the waterproofing a nice surface to be applied. Aquaproof 301BL or Tremproof 60 are both great products for this type of waterproofing along with using a protective sheeting prior to backfilling.
Good luck with the pour.
Andrew

Hi Andrew,

Thanks for the tips, much appreciated hearing from someone who's been here before!

I used plenty of little plastic tile spacer wedges to get the blocks level, but I didn't take the high spots off - in retrospect perhaps I should have, but really the result isn't that bad. There is probably less than 5mm difference in height over the entire 14m length of wall (which as a rank beginner I think isn't bad for a 2.4m high wall ), and since I have to make up another 100mm anyway to get to my required height I can just level off with concrete. I was planning to place forms along the top course of blocks to the correct height and just "over fill" the wall with grout.

I started out using a string line to keep a level, but over 14m I couldn't keep it from sagging ever-so-slightly so gave up on that and just used my eye and the spirit level.

As for the core fill, the Adbri documentation suggests pouring in no more than 1.8m lifts but I think I'll play it safe and go slower than that - four courses at a time over the length, then back to the start allowing a little time for the mix to stiffen. The pump operator who helped us with the slab pour was a real pro, so I'll probably call on him again for the wall. His rig is a fully remote operated boom, so there'll be no problem with placing the hose on the blockwork and we can go as slow as we like. Again per the Adbri manual, I'll be asking for 20MPa grout with a 600mm average spread, and between 7 and 10mm aggregate.

I have to ask, as you now have me worried - how common is it to blow out blocks with the pressure of concrete filling the wall? I'd hate to have to try and fix that on the run...

I wasn't planning on using a waterproofing coating on the back face of the wall - I have plenty of leftover concreting plastic (200um) and have installed a sheet of that, tucked alongside the drain pipe below the slab level. There's not a lot of wiggle room in between the wall and the cutting in any case - at one point, little more than 400mm and I don't think I'd like to be down there painting. Do you think a coating is absolutely necessary in addition to a plastic membrane? I'll be forming up a spoon drain above and behind the wall to keep surface water away, and the ag drain should take care of seepage... I hope

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Simon.

The adventures of an owner-builder in the Tallarook Ranges

Hi Simon

If Abri say 1.8m I'm sure they probably include a factor of safety. I used Boral blocks which are very similar and they had a max of 1.5m. The core fill takes quite a while to stiffen up but its certainly worth waiting before you get too high with the core fill in the one hit. Some commercial jobs try to push the limit and blow the blocks out but if you stay within the limit you should be ok.
If you don't waterproof the wall carefully you risk having a damp wall all the time. Its a difficult problem to fix if this is a problem so I would suggest you persevere with trying to get a membrane on there as well as the plastic. You can apply with a roller which enables you to get into reasonably tight places. My wall was probably 400mm as well and less in some places. I would also place an 80mm or 100mm aggi drain at the base of the wall covered with screenings to assist with drainage at the base of the wall. This will stop any water building up behind the wall potentially causing more dampness or leaks.
If you find it to difficult to waterproof there are positive pressure membranes that can be applied to the inside of the wall. They are applied like a render. You have a few options but I certainly do recommend applying a waterproof membrane if back filling up against the wall.
regards

Andrew

simon
took your advice and started a new topic "bog ugly"
some answers to your formwork questions there rather than hijack your thread
continuing to enjoy your blog keep up the good work

Not much going on this weekend, which feels a little odd I must say - it's Friday night and I'm back in Melbourne The building inspector came by today to have a look at my wall, and gave two thumbs up so we're clear to core fill next week.

So for the rest of the day (in between rain squalls) I made up a grout hopper out of old form ply which slots over the top of the concrete blocks, so we don't make an awful mess when the wall is filled. I've lined up the same guy who pumped the concrete for the garage slab - he's not exactly cheap, but he's a real pro and this is one job that I want to go according to plan. Enough knowledgable people have told me that core filling is a sod of a job that I'm not going to attempt to take any easy short cuts. (Like so many other things in this project, I've never done this before but I can't really see how pumping a wet concrete slurry into a cavity wall can be a difficult job. I guess I'll find out next week )

The hopper didn't take very long to put together (yet again, designing first in Sketchup saves a heap of time) - I didn't get a photo of the end result, but it's almost exactly the same as this:



While I had the saw bench assembled I also started cutting the timbers for my rammed earth forms - I got most of the columns cut before the rain set in again and put an end to the day

The rest of this weekend is a bit of a write-off from a building perspective - my eldest wants to go to the Grand Prix tomorrow, and it's Alissa's birthday on Sunday (not to mention the F1 race) so there'll be no more progress now until Friday, when we fill the wall.

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Simon.

The adventures of an owner-builder in the Tallarook Ranges

I asked the building inspector when he came by today about this, and his recommendation is the same as yours - a coating isn't strictly necessary, but I'll get a better end result (particularly less chance of salt "staining") with a coating in addition to the plastic layer I already have.

I scoped it out and I can reach pretty much the entire wall surface from behind on the hill, with a roller on an extension pole so that's what I'll do. Thanks for the advice



I already have an aggi pipe in place there buried in screenings, but I used what I had available (50mm). It's not in a sock either, which I'm advised by the building inspector is a requirement, so I'm going to install a second socked 100mm pipe alongside the first before I backfill. Can't have too much drainage...

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Simon.

The adventures of an owner-builder in the Tallarook Ranges