Decisions, decisions!

Very often, when people write blogs or produce videos about a project, they tend to show how they achieved a particular thing, without really going into all the background thinking and research that went on beforehand.

A bit like ‘Changing Rooms’, where all the materials used to magically appear, without the endless and time-consuming visits to B&Q and HomeBase. Slapping a coat of emulsion on the wall is the easy part. Choosing the colour from one of a dozen suppliers, the finish, finding the best price and then actually getting the stuff is the hard part! Not to mention keeping all the receipts and returning the stuff you don’t need!

The same thing applies to almost every single component and feature on the boat. To give a simple example: what should the lining be on the hull sides below the gunwale? The choices could be: horizontal boarding, vertical boarding or sheet material. You may think this is a decision which could wait till later in the build, but as with much of this stuff, there are a lot of dependencies. 

Let’s assume we decide on some form of T&G boarding. Whether it’s vertical or horizontal is going to affect which direction the supporting battens need to run. So if vertical boarding is chosen, we’re going to need horizontal battens – one at the top, one at the bottom and a couple in the middle, to support the board firmly. So we need to fix the battens to something. 

Now take a look at this picture.

The steels run horizontally, but there are only two of them. So there are two options: either fix vertical battens on first and then fix horizontal battens to them; or ask the builder to install the stiffening angles in the vertical. The problem with fixing two layers of battening is of course, the loss of cabin space. Two extra battens means 50mm less width!

So having decided to ask the builders to provide vertical side stiffeners, there is then the question of spacing. Having decided to use 75mm Celotex insulation on the sides, research shows that this comes in 1200mm x 2400mm sheets – unlike plywood, which is 1220mm x 2440mm. So the angles need to be set at exactly 605mm centres, to allow a split sheet of insulation to fit precisely between them without waste.

Back to the subject of the boarding. Next decision: what material? That decision will be made on preference for appearance, finish required and cost. The cabin on my boat will be 48’ 6” long – about 14.75m. The visible height of the side walls will be about 1m. So the area of the two sides will be just under 30m2. The next task is to work out how many metres of boarding will be needed; the problem being, most suppliers quote per metre run, not per square metre. Not helped by the fact that T&G is often quoted as, for instance, ‘Ex 19mm x 100mm’. 

 In other words, the T&G shape is produced from that section of timber, but the finished size will be a lot less. In the example shown, 11mm width is lost in the machining process. The thickness is fairly important, but the effective width really matters. With about 200 strips to be installed down each side, a few millimetres more or less will make a big difference! Frustratingly, very few suppliers quote the coverage width, so it really needs an enquiry or a sample. The example above does not give the effective width, so the dimnsion for the tongue needs to be deducted, giving an actual width of about 83mm.

Let’s assume by this stage, we have decided to use softwood T&G. An important consideration is the thickness of the boards. ‘T&G cladding’ from B&Q might look like a cheap solution, but will it be thick enough to not flex? What is the quality like? Will you lose large amounts due to waste? Will the standard lengths result in hundreds of wasteful off-cuts?

It may be that a board from another supplier, whilst more expensive per linear metre, might be a better bargain, if it provides a greater coverage width, is of better quality and results in less waste.

I like this style!

 Then there’s the question of the surface finish… paint or varnish? What colour? What finish? 

I’ve gone through this process in detail, just to show that even for an apparently really simple and straightforward task, like the lining of the hull sides, there's actually a great deal of thought and research required, particularly if costly mistakes are to be avoided.

I am working to a very tight budget for the ‘Calbourne’ build, so any money that can be saved in one area provides leeway in another. The remarkable thing is the sheer variance in price for an identical item from different suppliers. For example, I have pretty well decided on the Hyundai DHY6000SE diesel generator. I have seen this advertised at a range of prices from £1,720 to £1,193 – a difference of £527 for precisely the same item. Shopping around definitely pays!

This principle applies to even the most mundane of tems. Take the ballast for example. Again, there are numerous options, even after working out how much is needed. Steel offcuts are far heavier than concrete, but expensive; concrete bricks and slabs of various sizes are all contenders. The lowest cost per kilo are 'council' paving slabs - 600 x 900, weighing in at 60-odd Kg each. But that low cost needs to be offset against the back-breaking job of getting them into the boat and laying them. Other options include 600 x 600 slabs and concrete bricks weighing 3Kg each. If we go for the slabs, do they need to be one or two layers thick? If the bricks, do they need to be laid flat or on edge? The answers to those questions determines the height of the floor above the baseplate... which governs the arrangement of battening to be fixed to the steel bearers...

And so the seemingly endless iterations and calculations go on!

I now have a spreadsheet which runs to over 150 lines, which shows all the main items and components required for the build. In every case, I have identified the item, supplier, price and quantity required. This is the result of over 9 months’ spare time research, but has resulted in savings of thousands from the original estimate. It has been an informative and productive use of time during a period when no ‘hands on’ work could be done. This ‘hiatus’ time has also allowed early ideas and assertions to be questioned and either verified or discarded, so has certainly not been wasted. I’m hoping that by the time I start the actual work, I'm hoping I'll know exactly what I need, where I’ll be getting it from and how much it will cost!