Episode 99 Epoxy Floor Treatment: Shield-crete

Episode 99 Epoxy Floor Treatment: Shield-crete

Post Build

Kind of surreal, having the shed actually built.  I won’t say complete, because we all know a shed is never truly finished – there is always something more to do!

I can’t wait to start moving the machines and tools in, but I have to be patient just a little longer.

Firstly, I want to finish the floor, and as much as I would like to rush it, I am resisting so I can focus properly on it and do a good job.  So far I have acid etched the concrete so the epoxy can bond to it properly.  A day later (after the builders had left, and it was dry), it got a really good sweep, as there was a very apparent layer of loose concrete dust on the surface after the etching.  Surprising in one way – the acid seemed to do so little at the time, but not only was it really obvious the next day, a drip test demonstrated that a waterdrop now readily penetrates the surface, where it didn’t before the etch.

It is still as flat and as smooth as it was before, so the quality is unchanged, just the surface is now ready to bond to.

Next, it has been given a degreasing wash, using the caustic powder mixed with water that was supplied with the Shield-crete.  This was scrubbed vigorously across the floor (which made it evident it was still a bit dusty), then hosed and scrubbed off.  I then used a broom to sweep surface water off, and by the end of that, the water being brushed out of the shed was looking decidedly cleaner.  The surface is now clean enough to eat off!

Finally, I took the yard blower I have (Stihl) which can produce over 200km/hr wind, and used it to systematically blow the remaining surface water out.  Specific concentration was given to the expansion joints that had been cut, to ensure water was not pooling there, as I had noticed previously that a band about an inch on either side of the cut remained damp after even a warm day.

That was left to dry for the day.  I had a quick look tonight, and it has dried as I wanted, so the slab is now ready for the 2 pack epoxy to be applied, just as soon as there is enough light, and I have enough time, and energy to do it!  One way or another, it takes 3 full days to cure (you can walk on it after 24 hours), so there will not be any tools moved in this weekend.  I know – frustrating, but the ends definitely justifies the (painful) means.

It isn’t like I will be idle this weekend though.  After 24 hours, the glaze can be applied to the floor, so that is one thing that will keep it moving forward, and I need to get the downpipes connected to the stormwater so I can get the final building inspection signed off.  I’d like to get this done by Wednesday (the signoff that is), so I can get on with things.

Then, it will be a matter of getting the red-tongue I need for the mezzanine floor, as that will be used to make the path to bring the heavy machines from the garage to the shed.  That is a day worth waiting for!



Rubber Corrosion

Had an interesting experience with the rubber matting I have on the floor in the shed.  A week or so ago, I noticed a bit of an oil pool had gathered under where the SwordSaw was sitting on the edge of the table, and obviously the blade oil was slowly dripping down the blade and onto the floor.

Didn’t think anything of it (other than the mess itself that needed some cleaning up).

Noticed a pile of black,  insect-like flakes underfoot, and wondered where they had come from.  Looking closer, and I realised that it was the floor mat itself, slowly dissolving in front of me.  Guess the floor mat, sold for sheds etc is definitely not petrochemical resistant!!

Aldi and an unexpected shed upgrade

Was in Aldi earlier today (don’t shop there much, but their nappies are pretty good, and a reasonable price).  Came home with a bit more than I expected – an upgrade for the shed!

One of their ‘special’ buys at the moment is rubber flooring 6 pack for $20.  I bought a couple of sets – thought it would be good for reducing fatigue while standing at some of the tools for extended periods of time.  After laying what I had, I went straight back down for one more pack to finish the job – it covered more area than I expected, so instead of covering an area in front of a couple of the major tools as was my original plan, I found that just one more pack would pretty much cover the whole tool area.  (Each pack is 2.3m^2)

So now I have a nice soft surface to stand on while working in the tool section of the shop.  I don’t know how durable the surface is – only time will tell, but if it comes to that I could always put a thin ply (or similar) layer over the top.  It was very easy to lay – took minutes, so if I need to, it can be lifted to move a tool around.  Also, if some sections start wearing excessively, it will be a very easy and quick job to swap the worn sections for the less worn areas.

Aldi Rubber Flooring Pack

Aldi Rubber Flooring Pack

Laying the flooring

Laying the flooring

Flooring under saw and lathe

Flooring under router table, bandsaw and drillpress

Flooring under router table, bandsaw and drillpress

Not only does the flooring go together very easily, there is a generous supply of edging to give a finished look to the job.

Shed Construction – Foundation and Floor

I am currently writing some course notes for a shed building course that I’ve been asked to create for Holmesglen Tafe. The notes are kept pretty concise, so don’t expect pages of details, (they certainly could be – I could write a book on the subject- one day I might!)

Foundation Options

There are a number of options for the base of the shed, and what you end up choosing will be based on a combination of cost, location, and intended function of the shed. These obviously are closely related to the shed floor (and in some instances are one and the same). The forms that are available are obviously very closely related to the different options for house construction.

Dirt / Earth

In some cases, there may be no specific requirement for a shed floor, and therefore the foundations of the shed are thought to also be non-existent. This will very quickly lead to problems, and is definitely not recommended. That is not to say that an earth floor to the shed isn’t fine, and in some cases it is a good solution, but the foundation for the shed itself (under the walls) is still an important component.

A shed sitting directly on the ground is not only unsecured (and therefore highly venerable to wind damage), but is likely to corrode around the base very quickly. If you choose to have an earthen floor, you still need some form of foundation, whether this be on-grade, or concrete.

On-grade foundation

This form of foundation is particularly low cost, and very easy to construct. It isn’t strictly a permanent foundation, but never-the-less is quite suitable for shed construction. It involves placing the foundations directly onto the ground (a scoria bed, concrete or brick bed or earth) and on top of which is placed a treated timber frame (for the floor), or simply the shed walls themselves (and the floor can then be concrete tiles, or earth). A layer of damp course is strongly recommended, irrespective of the final choice. A bed of scoria or similar underneath is a good idea to aid drainage, and help prevent the foundation from sinking into the soil.

In any event, given the wind strength in Melbourne, it would be worth considering sinking a concrete pier in each corner (or pouring one) to have something to secure the shed to, rather than just relying on the weight of the shed to hold it in place in severe weather conditions.

Pier foundation

This is quite a traditional construction method, and is often used for houses, and decks. It involves sinking a grid of piers (concrete or treated wood) into the ground (often concreted into position), and then a wooden frame is constructed on top.

Concrete Slab

Another very common foundation (and floor) construction is the concrete slab. Even so, there are some different ways these are used (and laid). You can box up where the concrete is going to be poured, and once complete construct the shed on top, or take an easy route and build the shed on a basic form of on-grade foundation, then pour the concrete slab into the shed itself.

Sounds a bit rough and ready, but it can be effective, and you can be sure the shed isn’t going to be going anywhere after that! It is not my favourite solution. For one, it leaves the base of the shed particularly vulnerable to corrosion. On the other hand, the shed is secured down soundly, and it is very unlikely to have water penetrating under the walls.

Floor Options

This is closely related to the choices made for the foundations, and there are many variants available. These can include:


The floor when you don’t need a floor. One advantage – cost.

Wooden Flooring

This can be floor sheeting (either a commercially available form such as yellow tongue, or simply particle board, or similar), or tongue and groove boards, or decking. In any case, some form of underfloor barrier is definitely recommended (builder’s paper or foil, or at least a roll of plastic). There are advantages to a raised floor – services can be run under-floor (electricity, plumbing, dust extraction (if the shed is to be a workshop) etc. Having under-floor insulation obviously helps in the variable climate conditions.

A particularly good choice for workshops etc when you are going to be standing on it for long periods of time – it isn’t as hard on the legs and joints as a concrete floor. On the other hand, it is more expensive, you need a higher ceiling for the space lost underfoot, and it isn’t able to sustain the sorts of loads that a concrete floor can manage. Some woodworking (and particularly metalworking) tools can weigh in around ½ a tonne.

Wooden flooring can be placed on top of a concrete slab, which does provide a bit of the advantages of both options.

Concrete Slab Floor

There are advantages and disadvantages to all the systems, and the concrete slab is no exception. It is generally very strong and able to cope with significant loads, and particularly if you are going to be moving items around. It is relatively cheap, and by using something like a dynabolt, items can be secured rigidly to its surface. On the other hand, it is harder to stand on for long periods, so some form of rubber mat or similar would be a good idea, and if you laid it yourself, it can be tricky getting it really level. If you overwork the surface trying to smooth it, you can also find you have concrete dust being produced for a long time afterwards as well. They are also quite cold in winter, and trap heat in summer. One thing that is often missed is to seal the concrete once it has cured, as moisture can still easily pass through the slab if this is not done.

Both my current sheds (and a previous shed) have concrete floors, because as much as a nice raised wooden floor would have been ideal, cost and functionality were also considerations.

There are various grades of concrete – 20MPa, 25MPa and 28MPa. The 28MPa is relatively expensive, whereas the cost difference between the first two is only a matter of a few dollars per m3, so I tend to err on the side of 25MPa. That, combined with rebar and a 75 – 100mm thickness results in a very robust shed floor.

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