homebuilding.co.uk 199Did I beat the estimator?
On this occasion, no. It cost a lot more than
the budget because we opted for natural
slates rather than the concrete interlocking
slate/tiles that had been assumed on our
estimation. I have to hold my hand up here.
I hadn’t read the estimate too carefully and
I missed the fact that they hadn’t costed on
the basis of natural slate.
The extra costs came as quite a shock,
tempered only by the fact that Bruce, our
builder, didn’t charge any extra for laying
natural slate instead of the concrete ones.
I think he had always assumed that we
were going to be using natural slate as we’d
discussed it many times. The net extra
costs amounted to £2,118.84 but, as far
as our general budget was concerned, the
savings we’d made in earlier parts of the
build more than compensated. However,
we did make some savings, as follows:1
Bruce, our builder, did not charge
us extra for installing slates rather
than tiles as he is so used to laying slates;
this may not be the case with all builders,
so it is worth checking.2
The rooflights came with their own
flashing, so there was no need for any
extra leadwork — this resulted in modest
savings.3
I chose Spanish slates rather than
the far more expensive Welsh slates
(and, surprisingly, some of the man-made
slates, which can be more expensive than
natural slates). With any slate, you will
need to check for consistency of thickness
and size; inconsistent slates (which will
probably cost less) will never sit or
lay properly.4
I chose not to use a dry ridge
system (ridge tiles attached by
mechanical fixings and not mortar)
as I have never liked the look of them;
instead, we bedded normal concrete
terracotta tileridges (which lead to a saving
of £117.24).COsT-savinGTiPsFORROOFCOveRinG
l There’s nothing wrong with Welsh slates apart from the fact that
they’re frightfully expensive. Cheaper alternatives are available
from Spain, China and Brazil. (Note, Spanish slates are generally
considered to be better quality than those from China and Brazil.
We opted for Spanish slates, as the batches that we inspected at
our local suppliers proved not only to be the best in cost terms but
in the consistency and thickness.) As long as you can demonstrate
that the slates you’re proposing are fit for purpose and satisfy the
colour and size requirements, the local authority should approve
your choice of slate.l Slates can be natural or man-made. Strangely enough, some of
the man-made slates work out more expensive than the natural
slates imported from all around the world. Slates are laid treble
lapped, which means that if you drilled down through them, you’d
have to go through three layers. Each slate also has to be nailed,
which, again, ups the cost.l If you choose tiles, bear in mind that clay tiles are generally
more expensive than concrete tiles. In general the larger concrete
interlocking tiles work out cheapest, both from the point of view
of material cost and labour costs. The usual coverage is around 10
to the square metre and they can, therefore be laid fairly quickly.
Smaller plain tiles, on the other hand, usually have a coverage of
60 to the square metre, which means more battening and more
time needed to lay — and are subsequently more expensive to lay.
It’s not always necessary to nail each course and, in many cases,
every third row will suffice.l There wasn’t any additional leadwork required on my project.
The rooflights came with their own flashing and those were all
that was necessary and so savings were made here.The Build BUildCOsTs