48 house garden september 2019
#7 Over One’s
head: roofs
Roofs are the most elemental form of shelter in a house and
anessentialpartofthebuildingenvelopeKaRen newman shaRes heR thoughts on...
Climateisoftenthegreatest
influencerwhenitcomestoroof
shape,asthefundamentalfunction
ofaroofistoprotectagainstthe
elementsandextremetemperatures.
roofsareconstructedinvarious
forms–flat,pitched,vaultedor
domed(orinacombinationofthese)
asdictatedbytechnical,economic
oraestheticconsiderations.[1]
abuildingcanhaveamixture
offlatandpitchedroofs,butin
thiscase,theemphasisshouldlean
towardspitched.getthebalance
rightincreatingbothsheltering
(sloped)anduseful(flat)roofs.Build
flatroofsintheinteriorpartofthe
housewhereyoucanwalkdirectly
ontoonefromaroomonthesame
level.[2]
apitchedroofisthemostpractical
waytoallowwaterrun-offand
thermaltrade-offs.Itisalsothe
ultimatesymbolofshelter:studies
showthatchildren–eventhosewho
havegrownupinapartmentblocks- drawapitchedroof,twowindows
andachimneywhenaskedtoimagine
ahouse.
gabledorpitchedroofscan
accommodateadditionallivingspaces
intheformofattics.[3]
Inarainyclimate,avoidaroof
designthatrequiresaboxgutter
(whereslopingroofsmeet,orbehind
aparapet).You’relookingfortrouble
inthelongrun,asdampwillinevitably
finditswayintothehouse.Where
possible,alwaysallowadirectway
forwatertodischargeoffaroof.
The material chosen for the look
will influence the angle of the pitch.
Thatch is typically a slope of 45°; slate
aminimumof30°;andcorrugatediron
canbeaslowas8°.[4]
In terms of roofing materials, thatch
is a good insulator but requires more
maintenance than other options. slate is
prized for its durability but is expensive.
There is, therefore, an increasing move
towards using sheet metal thanks to its
durability, cost-effectiveness and energy-
efficiency. Metal roof panels reflect the
sun’s rays away from the house in summer,
and in the winter the radiant heat of the
homebouncesoffthemetalroof,retaining
theheatinside.
Flat roofs are traditionally reserved
for houses in arid climates, where the
need to drain water is of less importance.
however, with advances in waterproofing
materialsandtechniques,thisisless
relevantinmodernarchitecture.
roof overhangs are often cut back
in contemporary builds, but they are
important as they protect doors and
windows from rain. [5] similarly, with
pitched roofs, there is a temptation to
do away with gutters for aesthetic gains,
but these are vital in protecting the
walls from damp. gutters should be
the same colour as the roof, and the
downpipeshouldbethesamecolour
astheexternalwalls.
Bringtheeavesofaroofdownlowat
placeslikeentrances,wherepeoplepause.
roof gardens can provide additional
living space, as well as greening buildings- thinkofMediterraneantownswhere
almosteverybuildinghasahabitableroof.
north-facing sloping roofs are great
for accommodating solar panels, as are
flatroofs.n
8 newmanarchitecture.co.za
@newman_architecture_design
1
3
4
5
2