Aug 2021 - Rain Drain and Decking Prep
Rainwater
I needed a solution for rainwater coming off the roof, guttering is the standard method, the question is where to route the water to.
Option 1: Soakaway
Downsides: no idea how to build a soakaway
Option 2: Tap into drain
Downsides: no idea how to tap into a drain
Anyway, there was a drain very nearby that took rainwater from a garage roof so once I excavated a bit I noticed that there was a T junction that looked pretty easy to tap into.
I also measured the fall between the T junction and my expected gutter exit at floor level and it was over '1 in 40' so this looked like a good option and I proceeded to ignore the soakaway idea.
Method
I picked up a few parts from screwfix, some waste pipe, some 90 degree angles, a flexible coupler (because there was slight kink to deal with) and a little rubber thing that goes from waste pipe diameter into drainage pipe diameter.
Pretty straight forward to install - dig a trench, connect the parts up, lay it on soft ground pea shingle in most places, then back fill with soft ground (no rocks or stones).
It doesn't look it but the ground is sloping towards the drain
The next day I had another go at this as I realised that the end of the pipe sticking up out of the ground was visible when viewing garden room from the front at certain angles. So I moved this part further down the side wall which meant getting more parts:
1. longer pipe to extend the distance
2. replacement 90 degree bend because removing the original with a hammer turned out to be a terrible idea - those things really disintegrate!
Decking Ground Prep
At this stage I also got the levels sorted to accept the decking.
I'm planning on using those adjustable plastic plinths that all the decking companies seem to sell - they seem like a nice solution but time will tell. The building is raised above ground level on the right hand side, but not so much on the left hand side (50mm on left and 250mm on right). The timber decking base is 100mm thick which meant it would need to sit 50mm below ground level. But I didn't want the base of the left hand side sitting on the ground, I wanted to ensure it was raised up out of the way of water / moisture sittin on the plastic pedestals . Therefore I needed to dig down a bit on the left in order to have the deck supported at the right height. I also wanted a reasonably flat and solid platform to put the pedestals on. I considered putting down hardcore but decided just to compress the ground with a tamper to create a solid base.
Pedestals
I found out the smallest pedestal size and dug down enough to accomodate both the pedestal and the timber frame (plus a bit of wiggle room). The pedestals come in lots of different sizes from about 30mm up to about 300mm (in fact I think they can be stacked and go even higher, even up to metre or so I'm thinking but you will need to check that). The ones I bought were I think called Rhinodeck or something but there are loads of suppliers for these things. Anyway, they each have a range, for example 50-70mm, or 200-300mm and you have to buy the right ones for your application, and it isn't all that straight forward to work out what you need
Notice the pile of dirt in this picture that I will 'deal with later'. Turns out 'later' is a time, far, far into the future....
Levels and parts ordering
So once it got a bit darker outside, I set up a laser level pointed at the height on the outside wall where the bottom of the timber deck frame would be (this is the same level as the top of the pedestals, obviously). Then I went around with a tape measure on every location of the pedestals and wherever the laser intersected the tape, I noted the measurement and wrote it down. I think I spaced mine every 500mm, they are rated at over a ton each, so the loading wasn't an issue, just span, and with a 100mm x 50mm timber for the base, spanning 0.5m across the supports is not an issue in the slightest.
Here is the 'document' I created telling me the required heights for the individual pedestals.
Once I had the heights I created a simple table of the exact parts I needed and quantities of each and then I went online and ordered them. What could possibly go wrong.
Here are the parts as they arrived, some assembly is required and it isn't as straight forward as I would have liked to assemble them. The assembly takes seconds for each one, but knowing which parts to put together is the slightly tricky part as you have not only different base heights, but also different 'stalk' heights. I had to go on the website and figure out which parts to mate with which other parts in order to build up the actual parts I ordered. I mentioned to rhinodeck that this was harder than it needed to be and they agreed and planned to sort something out better for next time, like a simple chart that comes in the box, rather than just the puzzle pieces.
Martin
cool idea.
