Installing The Rear Sliding Door

by Chris Bates
11th September 2019

Creating a good connection with the garden is a key goal for any self builder – the question is, do you achieve that with sliders or bifolds?

We faced that conundrum with the Build It House, and the original concept drawings showed bifolds, which concertina back to give you almost totally clear garden access when open.

The downside, of course, is that there are more panels than with sliders – so the latter gives you a better glass-to-frame ratio. In the end, that’s what swung the decision for us.

We’ve gone for the Build It Award-winning theEDGE2.0 thermally broken aluminium slider from IDSystems, on a supply-and-fit basis. It offers slim sightlines of just 20mm and good performance for weather tightness, security and energy efficiency – all at an appealing price point for such a high-spec product.

A long-established UK glazed door supplier, IDSystems is still family owned and has a knack for innovation, so was a natural fit for this part of our project.

Ordering the slider

I’d assumed we’d need a fixed frame at one end of the run, with the doors sliding on a triple track (one of which would be redundant). But David Clarke, IDSystems’ marketing manager, suggested a plant-on panel could give a better aesthetic – largely because it would allow
for a narrower twin track and a thinner external frame.

IDSystems Installation

1. The IDSystems install team grind cut the last few bits of high concrete

It was an easy decision to go with the plant-on: the fact is sliding doors are kept closed most of the year, so it’s all about maximising that view through the glass. When they are open, theEdge2.0’s panels will stack flush, keeping sightlines nice and slim.

While we could have colour-matched the unit with our windows, because those are in timber rather than aluminium, the hue would never be exactly the same. So we decided on RAL 7016 anthracite grey, which looks sleek and will blend into the garden setting.

Installing sliding door cill

2. The DPM is taped and glued onto the door cill

The double-glazed panels have low-e toughened glass on the inner pane, and 8.8mm clear laminated glass externally to deliver on safety and security. Once we’d finalised the design, IDSystems’ contracts team got in touch with drawings and documentation to sign.

No stone is left unturned at this stage: after all, it’s not in anybody’s interests if the install team turns up on site to find that the doors don’t fit properly. Among other details, the six PDFs I received included in-depth notes on what to check to ensure the structural openings are correctly prepared.

By now, most of the work was already done – and I’d been in touch with IDSystems at key points to ensure they were happy. The ICF closers to the sides of the openings provide fixing points. At the base the track can be screwed directly into the concrete, and into timber at the head.

Assembling door frame

3. Assembling the frame took less than an hour

The few bits left to do at our end included cutting the insulating formwork back to the polystyrene closers, chipping out the corners of the opening where the concrete pour was slightly over, and getting the screed in.

With a five-week lead time between order and delivery of the doors, there was plenty of time to sort this – although the final bits of trimming happened on fitting day.

Final preparations

When IDSystems’ install team, Paul Shorter and Mark Williamson, arrived on site, the first thing we did was check out the structural opening to make sure it was as expected. Pretty quickly, we noticed a discrepancy – the screed had been poured to a depth of 55mm (rather than the intended 40mm).

Leveling out doors

4. Ensuring everything’s level and square is crucial – otherwise it just won’t run smoothly. This stage is probably the most time-consuming

It looks like Screedflo did this to marry up with the insulation and underfloor heating build-up in the WC, which makes sense. But this was the first Scott and I had heard about it! Thankfully, we had enough space at the head to raise the sliders up a little higher without compromising the look – and as we’ve not yet specified the patio make-up, we can easily accommodate this.

It does mean we need to cement fill or dry-pack beneath the bottom track. I’d imagined we would fit the track so it’s perfectly flush with the tiled finished floor level (FFL), which will sit 17mm above the screed. But Paul suggested going for a 3mm-4mm lip.

Glass panels on doors

5. One of the glass panels is lifted into position. It’s then clipped into place with special beading

This is just enough to reduce the amount of debris that might get kicked into the running channel, but not so high it becomes a trip hazard (apparently anything up to 7mm is fine). What’s more, apparently if you go completely flush, the tile grout lines are much more likely to crack.

The next big question was how deep the setback should be (ie how far back the door should sit in the external wall). A twin track is much thicker than a standard window frame – so it’s never going to match up completely – while the two outermost panels are at different points within the frame depth (in fact, the plant-on is slightly proud).

silicon sealant on door

6. Silicone sealant is run where needed, before the whole unit is wiped down using a special cleaning solution

It’s the same with any slider, of course, but accentuated where we have timber cladding on one side and render on the other. We agreed that the best visual effect would be achieved by lining up the plant-on so that the full thickness of the larch cladding is on show.

Installing the doors

With the details nailed down, IDSystems’ fitters cracked on with the install. Paul and Mark worked as a team, one putting together the frame segments, the other prepped the bottom of the opening with spacers and clearing any last remaining areas of high concrete.

The damp proof membrane (DPM) is incorporated into the system – taped and glued to the cill – rather than being laid into the base of the opening. Once the full 4,208mm (H) x 2,488mm (H) aluminium frame was assembled, the guys lifted it in and got to work aligning it. Everything needs to be pretty much perfectly square, within a tolerance of maybe a millimetre or two, to ensure the running mechanisms operate smoothly.

Then there was the issue of getting the setback perfectly right to show the doors and the cladding (not yet fitted alongside the door) in their best light – which had Paul nervously quadruple-checking dimensions before the screws went in. I’m delighted to say he got it spot on!

The glass panels on a slider like this weigh in at over 100kg each, so they’re added on site after the frame is squared, levelled and fixed. The team fits the empty panels first to check the operation and locking systems, before inserting the glass. Interestingly, the doors actually slide at their smoothest when they’re fully assembled and heavier.

The final piece of the puzzle was to clip in the beading and re-test the lock positions (which Paul did by attaching strips of masking tape to check the alignment of the multi-point). A few minor adjustments later, and our glazed slider was fully installed – all in less than a day.


IDSystems’ literature asks for the owner to be present for a handover – and I have to say it was a useful exercise.

Paul went through the long-term maintenance instructions and gave clear guidance on how to
care for the sliders over the coming days and weeks on site. Your first thought is to cover the doors, for instance, but you need to give them 48 hours for the seals to fully dry before doing so.

They shouldn’t be operated for at least 24 hours either (cue all keys being taken off site) and, once you do open them, it’s a good idea to protect the track to avoid construction debris getting in there and potentially damaging the mechanisms.

There’s a bit of work for us to do to finish it off. For instance, we need to fill in a small bit of screed, which we were expecting – we deliberately left it a little short so that it wouldn’t get in the way of the install. When we do that, we’ll need to ensure we wrap IDSystems’ DPM up the inside of the frame.

Other first fix joinery

There’s plenty more going on at the Build It House site to keep things ticking over at this stage of the project.

Here’s a quick look at some of the carpentry jobs that, while small, can add up to a sizeable chunk of time:

Door linings


Decisions abound as you get into the first fix phase of your project – and one that will have a big impact on the finished look is the internal doors, which will be supplied by JB Kind. We initially planned to use pre-assembled doorsets, but the lead times were longer than we’d hoped and there are less size options than standard doors.

Either way, we still needed to install the liners. These sit slightly proud of the face of the studs, leaving enough space so that the boards and plaster skim will give a flush finish. We’ll look at our internal door choices in more depth next month.

Basement stairs

installing basement stairs

We’re holding off fitting our feature staircases for as long as possible, with the aim of protecting them against the dirt and grime that’s inevitable on a building site, But there’s still work to do at first fix stage. Kloepping TSS, our stair provider, was recently on site to install the aluminium profiles to give a fixing point for our basement flight (this image shows Meinholf Kloepping tapping in for the fixings).

We need to get this done now, as it will be covered with plasterboard on the inside face. Meinholf’s visit to site revealed some of the stud walls in the basement needed to move slightly to allow enough space at the bottom of the flight to meet Building Regulations. Drewett & Hunt got this sorted within a couple of hours.

Pocket door systems

pocket doors

This style of door can maximise floorspace, as you don’t need to account for leafs swinging into rooms or corridors. We’re using pocket doors in two key locations: the opening between the hallway and snug; and from the master bedroom into its adjoining rooms (a walk-in wardrobe and an ensuite).

Due to the open-plan nature of the ground floor, we need FD30 fire-rated doors at the snug. We could only find one specialist, Eclisse, that currently offers an FD30 pocket mechanism; happily, they’ve been very proactive and came on site to oversee the installation.

Window boards

fitting window boards

We’ve opted for pre-primed MDF window boards for most of the house, with a bullnose (gently rounded) front edge that will soften the contemporary edges of much of our decor. Affordable, widely-available and great for painting, they’re a de facto choice for many self builders.

They need to be installed prior to plastering to ensure the best finish. They’re simply cut to shape, packed with spacers to get a level finish, foamed to guarantee airtightness and nail-gunned into position.

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