With the beam and block ground floor completed, construction of the main walls has zoomed ahead at a rapid rate of knots, and we can now contemplate the next major job: hoisting a humongous pair of steel beams skywards. Without these critical components in place, work couldn’t begin on the main upper side gable wall and main roof structure. So I was pleased to see a posse of builders’ vans arriving promptly one Saturday morning.
Attempting to raise two 6.6m-long Universal Beams weighing 442kg each up to ceiling height is obviously a daunting and potentially dangerous task. But this part of the design demanded something substantial to support the towering upper gable wall soon to be constructed over the ground floor living space.
Main Walls Rising
Getting the lower main walls built first required air bricks and periscope vents to be fitted at regular intervals around the ground floor, and the gaps in between neatly filled with small slip bricks. For the walls below ground we’d used super-strong engineering bricks, but for the visible courses up to DPC (damp-proof course) I’d chosen nicer looking Northcot reds to contrast with the smooth white rendered walls above.
On the inner leaf, a 450mm DPC was draped down so it could later overlap with the damp-proof membrane — in effect ‘tanking’ the lower walls and floor.
As the inner leaf rose upwards, the blockwork was lined with 50mm Kingspan phenolic foam insulation boards. Given the choice, brickies generally seem to prefer mineral wool insulation batts on the grounds that they’re easier to stuff into place, but they had no problem cutting and securing the rigid boards with red plastic discs clipped over stainless steel wall ties.
Rather than fitting the windows as the walls took shape, I thought it safer to defer this to a later stage for fear of inviting damage, so we knocked up some wooden templates to use as temporary substitutes. I also took the trouble to print out larger scale drawings with the opening sizes clearly highlighted as an aid for the brickies.
Our chosen window supplier, Jeld-Wen, recommended openings 12mm wider and higher than the frame size and, aesthetically, we also needed to factor in about 20mm thickness of render to the outer reveals.
To date, my carefully choreographed programme of material deliveries has been running remarkably smoothly. The only problem we’d encountered concerned a small number of 7N Thermalite trenchblocks specified by the structural engineer for the internal walls supporting the steel beams.
Despite being in short supply, Buildbase managed to get a pack over to us. But upon closer inspection these turned out to only be standard 3.6N strength and had to be returned. In fairness, this was an easy mistake to make because, rather puzzlingly, the plastic packaging was silent on this key factor, and blocks of different strengths look virtually identical. Thankfully, Buildbase managed to pull out all the stops to come up with the goods.
While on the subject of suppliers, to date, one of the most impressive firms we’ve done business with is a specialist outfit called Steelfast who came recommended by builder Godfrey. Either way, their prices were competitive and the service efficient, delivering our custom-sized, pre-drilled steels the following week.
The only downside was that the delivery driver plonked the giant beams down on the drive next to the lane outside, so we had to risk temporarily leaving £1k worth of heavy steel in full view of passing dog walkers. Fortunately in this part of the world very few opportunistic thieves come fully kitted out with heavy lifting equipment!
Moving the Steels
I was intrigued to know how the builders were planning to move the steel beams towards their intended destination. In a scene that would probably have been familiar to the ancient Egyptians, the task was accomplished by rolling them over a series of short scaffold poles (aided by a mini-digger rather than teams of slaves). Each beam was then individually raised up with the aid of two hand-driven chain-winches, looking similar to upturned bicycles.
Care was taken to prop the sides of the ascending steels with planks of wood as a safety measure since one false move could clearly have had devastating consequences. Once both steels were safely in place, fully aligned and supported on their engineering brick end bearings, a series of M12 bolts were inserted through pre-drilled holes to securely tie them together. When done, a palpable sense of relief and achievement resonated around the partially built extension.
The guys had certainly earned their pay that morning and, coincidentally, the first contractual payment was now due. Most builders can recount shocking stories of non-payment, but Godfrey had a frightful tale about being duped into paying a sizeable sum of money into a crooked bank account hijacked via a scam email.
So having texted me his bank account details for payment it seemed prudent to transfer a small initial sum, to guard against scamsters and ID theft, with the balance to follow once verified. Happily the bank transfer went without a hitch. All that remained for me to do was call building control to arrange their next inspection.