The time (and money) has finally arrived to knock down a 22 by 10 foot
corrugated iron garage, that could easily already have been 20 to 30
years old when we moved into the property almost 40 years ago, and
replace it with a concrete sectional garage (most likely supplied,
delivered and erected by a company called Nucrete https://
nucrete.co.uk).

The garage was already looking the worse for wear when we moved in, not
helped by the fact that whoever had laid the original concrete base,
seems to have started running out of materials about halfway through the
job.

It looks like they'd started off ok at the back end, finishing off the
front 7 or 8 feet by simply laying a thin skim of concrete directly over
the soil which rendered it unfit for use as a workshop come garage.

Our finances at the time were rather stretched so this upgrade project
had to be parked on the 'back burner' along with all the other higher
priority jobs that would just have to wait until we could spare the
money. The garage was simply the most costly and least urgent job so
consequently remained at the back of the queue until now.

I've researched the options and concluded that a concrete sectional
garage offers the best durability for the price over brick or wood
constructions. I'd had experience of erecting a 6 by 8 foot concrete
panel shed almost half a century ago in my early twenties whilst still
quite fit and living with my parents so have an appreciation for the
durability of such construction.

The difference between the shed I'd erected in my parents' back garden
all those years ago and today's 'concrete sectional' garage/shed
construction being that back then, the panels were inserted between the
pillars in 'landscape' orientation (4' by 2' and 3' by 2' panels afaicr)
as opposed to the 'portrait' orientation used by Nucrete (30 or 60 cm
wide, 6' 6" or 7' tall reinforced concrete panels).

This is of academic interest since I won't be having to do the actual
erection work this time (nor will I be laying my own concrete base either
now I have more money than fitness).

Looking at the dimensions of the garages being offered by Nucrete, I was
quite surprised at how closely their 22'3" by 10'5" option matched those
of the ancient 22'3" by 10'2" wide corrugated construction that currently
stands at the top of our driveway. I don't think the extra 3 inches on
the width of the replacement is any issue regarding planning permission
(permitted rights). The height of the new garage, if I opt for the
cheaper single slope roof will be well less than the existing single
slope roofed garage.

That just leaves me the task of having the old garage demolished and
taken away and the concrete base brought up to standard ready for
delivery and erection of the new garage.

The base is one area of concern since the back end, despite the
remarkably little ingress of surface water observed during a recent rain
storm, is about 7 inches below the level of the garden and I'd like to
eliminate any risk of such ingress with the new garage by raising the
level of the concrete base another 7 inches rather than rely on mortar
fillets between the bottom of the panels and the base as my only defence
but I fear I may be underestimating the effectiveness of such weather
proofing using just a mortar fillet on the inside only as specified by
Nucrete.

Also specified by Nucrete is the requirement for the base to be 6 inches
longer and wider than the garage. Since the old garage has a three course
high brick retaining wall cemented to the bottom of the corrugated iron
sheet wall panels, I'm assuming this retaining wall is laid directly onto
the outer edges of the concrete base, inferring a base sized a good 9 or
10 inches wider than the measured dimensions of the existing garage which
should meet the requirements of the new garage once the site has been
cleared ready for another 7 inches of concrete (reinforced perhaps?) to
be laid on top.

The problem with raising the base height by 7 inches is the need to
extend a ramping section where it abuts the top of the driveway. Sticking
with the original base height obviates this requirement but it means I
lose the "Dry by design" of an elevated base as well as the expense of
digging out the soil underneath the skim of concrete to bring it up to a
minimum standard versus just simply pouring another 7 inches of concrete
on top of the whole base (with or without rebar).

I have a feeling that there's not a lot to choose, cost wise, between
those options so raising the depth of the base seems the better choice in
the light of the improved dryness that would be gained. If a job's worth
doing at all, then it's worth doing properly IMO.

Anyway, that's the situation and my thoughts on the project. The advice
I'm seeking are opinions on my proposed supplier, Nucrete who are based
in Bradford (I'm in the NW of England btw), including any suggested
alternative suppliers and any thoughts regarding the best way to bring
the existing concrete base up to standard.

I plan on hiring a local contractor to clear the site down to the
existing base and, quite possibly the same (if not another contractor) to
deal with bringing the concrete base up to standard one way or the other.

Also, I'd like to build a small brick or concrete emergency generator
shed (6' by 4' by 6' high?) at the rear, possibly on an extension to the
concrete base along with buried ducts between the house and the garage to
run electricity supply, co-axial and ethernet cabling.

I've considered having this done using a moling service but there are
waste water drains crossing the route so I might have to run these on
overhead trunking or catenary wires instead.

I think I've covered everything but please feel free to mention any
oversights you think I should be addressing.

--
Johnny B Good