Invent Design Make

Step 19 – Preparing the Entryway

Preparing the opening ready to fit the frame is really important.  In this crucial step, we make sure the base is completely level, is properly drained and all tidy, ready to accept the door.  We have recruited Dave to help with proceedings, and we level up with an SDS drill with a rotary stop and chisel bit.  This is sooo much more effective than an old school hammer and chisel.

We also dig a little drainage channel that runs across to a convenient drain just to the left of the opening.  As you can see we keep the garage door in place and closed for this, to help stop debris and dust filling the shop. Incidentally, we did a little comparison test:  it seems the mains SDS+ has a fair bit more grunt than the 24V battery SDS you can see below (also the battery one has no rotary stop – so no good for chiselling).

Before we started altering anything we spent some time thinking about where in the opening it would go.  The decision was based on a number of different factors, like where the neighboured ones were, how setting it back a bit would offer some weather protection, and what looked good.  In the end we went for about middle.  Using the massive spirit-level we drew on some vertical lines with chalk (the yellow is what we are using, blues are rejects).  It looks wet below because we just did a water test, poring a watering can full over it, to check the drainage is all good.

Once we had chipped down the level, we put down a layer of damp proof course (DPC), which is basically just a length of thick robust plastic. On top of this will rest a number of oak shims, bandsawed to equal size.  The threshold of the frame will rest on these shims, just to keep it off the ground, and any possibility of dampness.  They can also be used to ‘fine tune’ the very slightly bumpy concrete and thus get the frame dead level.

The DPC is folded up at the back and sides, this is just to make sure that water will tend to move from the inside to outside.

Keeping a close eye on the level we make a completely flat platform of shims, spaced every 10cm or so.  If we get this bit right, the rest should be good too, so it is important to use the biggest level possible.  We bought this super long one specially and it has since come in handy for a number of other jobs, and also been useful as a straight edge for checking planks of wood.