Saturday, November 16, 2013

Shelter and Comfort

“The sun did not shine. It was too wet to play. So we sat in the house. All that cold, cold, wet day.” Dr. Seuss

A richly detailed bungalow with broad sheltering eaves repelling the Vancouver rains

Rain was falling steadily when I began this post, marking Victoria’s autumn shift from drought to damp and serving as a reminder to ensure drainage systems are working properly so that comfort is ensured. Keeping moisture out of houses has been a running challenge since man first bent branches together to roof out a patch of the sky – especially in damper climates like ours.  Recently it’s become resurgent, as newly engineered flaws in roof and wall designs let moisture invade cavities that can’t dry out due to plastic vapour barriers. Rot consumes its wooden host with startling speed when walls can't dry out, especially if second-growth timber is involved!

Rot moves quickly in a new house once wood becomes soaked

All building eras have their failings when it comes to managing water, as do some famous modernist architects. All house types require ongoing attention to water management, adding to the bane of home ownership and affecting how much we have to be involved in order to dwell comfortably. I’m fortunate in that my house, the Hubert Savage bungalow, does a reasonable job of keeping rainfall and moisture out of walls and foundations. For a century-old home, the general conception is fairly sound, meaning that water is successfully managed from roof to ground and then dispersed.

A gable roof form is ideal for shedding rainfall and generous eaves protect the walls

The challenge for architecture begins with a roof that’s impervious, shedding water and sending it away from the building's foundations. One advantage of early bungalows is the way their roofs push well out over their walls, protecting them from being directly rained upon. These sometimes exaggeratedly broad eaves create a distinctly sheltering look too, a hallmark of the early California style and a feature that’s central to its lasting appeal. A relatively flat, projecting roof defines the one-story building’s style.

A prairie house by Frank Lloyd Wright sheltered by a projecting roof form with deep eaves

For bungalow designers, exaggerating the roof’s form reinforced the impression of the house as a haven or refuge from inclement weather. Generous treatment of the roof imparts a sense of security and coziness, a form-play that Frank Lloyd Wright used to great effect on many of his massive Prairie-style houses. But a house can only provide a cozy haven if it actually delivers a dry interior!

The umbrella effect of broad roof overhangs shields the wall beneath them from direct rainfall. Any rainfall that does reach the walls is then sealed out by siding that directs it downwards to a device known as a water table – a slab of angled wood then sends any moisture out beyond the foundation. This is a very useful feature, as many California-style bungalows sit close to or even directly upon the land.

Gutters, downspouts, water table and perimeter drains: water caught by the roof and then dispersed safely to ground

Of course water collected by the roof still has to be removed or it cascades over the edge, splattering on the ground and splashing wet organic matter back onto the building. This might be alright in drier parts of the country, but here in the Pacific Northwest it would guarantee mossy, damp walls and develop ideal conditions for rot. Here on our wet coast, gutters and downspouts are needed to complete the job of moving rainfall safely away.

Backsplash: water and organic matter splashed onto walls, here caused by nearby trees

The Savage bungalow is a bit optimistic in the configuration of valleys and gutters used to carry water away from its substantial roof forms. Being cross-gabled, valleys happen where roof planes intersect, creating heavier flows of water. These valleys discharge into small, narrow gutter runs accessed at sharp angles, which send water to ground via metal downspouts.

Valleys debouch into narrow gutters and small diameter downspouts: a weakness in conception

Because this bungalow was built in an oak meadow, there’s a lot of tree litter moving across the roof that tends to collect where valleys and gutters intersect. In a downpour, this debris moves suddenly into the gutter, where it tends to plug the downspouts and cause overflows that run back over the soffits or splash mud back against the building.

Water collected in valleys easily overruns even modern gutters and downspouts in a downpour

There are no exceptions to the implacable laws of physics: water is either managed systematically downwards to ground and safely dispersed, or it invades crevices and dampens materials. So this all has to be thought out carefully and methodically as part of design in order to protect the integrity of the house and the dryness of the interior, a process many designers continue to struggle with.

Even stone buildings have to have their joints and seams maintained in order to repel moisture

A fashion of the pre-WW1 era was to mate narrow wooden gutters with small diameter downspouts, which looks just fine but makes plugging at the intake frequent. Periodically then, one finds oneself up on a ladder freeing the downspouts (which is awkward, given the lie of the land, especially if it's at two in the morning).

One bane of home ownership: regular cleaning of gutters

Another flaw I’d be facing at home but for this building’s fortunate placement on a rise, is the lack of infrastructure to conduct water away from the end of the downspouts. Much of the water collected at the front of the house is simply left to drain down the slope, which it does quite handily. Unfortunately, it also to some extent drains under the house due to its placement on the edge of the rise.

Water carried off by the slope and a path mimicking its movement

At the rear of the house the conception for dispersal is a little more sketchy. Here the building sits close to the ground on a minimal crawlspace, placed over a slight hollow that deepens towards its southeast corner. Here is where water wants to pool in a downpour during the rainy season. An effort has been made to drain the area with a pipe aimed down the slope, but unfortunately due to bedrock it's set too high to be really effective. Roof water at the back of the house was originally sent into a set of narrow clay perimeter tiles, which of course clogged quickly with roof debris (don’t they all!). Eventually these were decoupled and water was simply left to spread onto the ground a foot or so from the wall, ensuring some of it drained back under the building. One of my early interventions was to have installed a wide-diameter drain (with a clean-out) to collect the roof runoff and carry it towards a rock drain where the land slopes away. This helped reduce the pooling tendency under the building substantially.

A building set directly on the land complicates managing water, which has to be effectively removed

Another intervention saw replacement of the three worn-out roof layers (two asphalt on top of the original 1913 stained cedar shingles) with a new cedar-shingle roof. Despite their thinness, seasoned cedar shingles are superb rain shedders. And if they’re high grade material and properly installed, they can last a fairly long time. Overall, this system of gabled cedar roofs with cedar gutters and metal downspouts has proven a fairly effective and durable method of keeping the house dry (with the help of the beveled wooden siding, of course), and therefore comfortable. On the anniversary of its first century of use, the Savage house shows no signs of any moisture ever having penetrated its ceilings or walls (touch wood!).

Houses have always afforded us shelter, but as historian Alan Gowans (The Comfortable House) points out, before 1890 they were rarely designed with comfort built in. Delivering a truly comfortable dwelling became an explicit aim of development with the advent of early C-20 bungalow home. Invading dampness is comfort’s persistent enemy, and certain novel features incorporated into bungalow design did a good job of keeping it out.

Water pools on flat roofed buildings, affecting the life-span of the rubber or plastic membrane

Friends of mine who live in a much newer dwelling have not, however, been quite so fortunate. They inhabit a flat-roofed modernist house whose rather drab exterior belies its interesting, well-lit interior spaces. But that flat roof has caused them no end of trouble, regularly needing emergency attention for unclogging, draining, patching or wholesale membrane replacement.

We are often unaware of water pooling because a flat roof is only glimpsed from above

This is not a new problem of flat roofs – it has in fact plagued modernist houses from the outset. It turns out that the public's instinctive preference for gable roofs isn't after all – as the militant modernists would have us believe - mere sentiment. Gabled (inverted vee-shaped) roofs actually make really good engineering sense because their angles cause water to be shed effectively. However, on flat roofs, water's much more prone to hang about, degrading surfaces and damaging seams.

"Like a river down the gutter roars the rain..." Longfellow

FLW at the Guggenheim
Frank Lloyd Wright’s famous flat-roofed buildings often had problems with leaks, a fact he once dismissed cavalierly by saying “if the roof doesn’t leak, the architect hasn’t been creative enough”. Le Corbusier, whose first and most famous flat-roofed house was also plagued by leaks, responded with similar arrogance: “ Of course it leaks. That's how you know it's a roof.” These two renowned architects worked at opposite ends of the modernist spectrum, Wright being an imaginative romantic who embraced nature (albeit at times rather abstractly), Le Corbusier a clinical minimalist who wanted buildings to be machine-like and so ignore nature entirely.

It should be said that there are no inherent reasons for buildings to leak, only designs that don’t sufficiently respect the implacable laws of physics. Water invades, by multiple avenues, and its accesses have to be closed off definitively by design, and through careful sealing.

Fallingwater, placed directly over the falls, so as to fuse building and feature into one

Wright’s famous masterpiece, Fallingwater, though still revered architecturally, nonetheless had continuing moisture problems. This derived in part from the building’s eccentric placement directly above a waterfall, a choice Wright made in order to fuse physical feature and dwelling into a single organic whole. Aesthetically this arrangement continues to inspire an interest that borders on obsession, attracting over 150,000 visitors annually (4.5-million-plus in total since being opened to the public).

Dramatic cantilevers project interior and exterior spaces out from a solid stone core

Wright’s stepped structure is cantilevered out over the stream, capturing the sounds of the falls for its occupants in every room. Bringing the falls inside audibly is one thing. Less desirably, this placement allows them to enter the building as moisture, in the form of humidity and damp rising constantly from their action. This moisture infiltrates the building with unintended negative consequences.

Wright used stone, glass, wood and fabric to good effect in Fallingwater's interiors

Built for the wealthy Kaufman family of Pittsburgh as a recreational villa, Fallingwater suffered so much from dampness that Kaufman-senior nicknamed it “rising mildew”. The problem of damp invading structure was compounded by engineering flaws within its dramatic cantilevers of reinforced concrete and steel, which allowed Wright to step the building down the landform. The cantilevers break up the massing while gaining space for outdoor living, simultaneously functioning as roofs for the internal space beneath them. Unfortunately, there were problems with the load carried by the reinforced concrete, which meant early sagging and worrisome cracks. These fissures expanded and contracted as humidity levels fluctuated, stressing flashings and opening avenues for moisture to work its way back inside. Kaufman’s son reports opening up areas only to discover sopping wood and soaked insulation, fueling mold and rot.

Modern yet intimate spaces: severity softened with wood, artifacts

And when it rained, things got way worse. Fallingwater actively leaked, even in Kaufman’s treasured study, a fact he informed Wright of with some impatience - who in turn suggested unhelpfully that he should move his chair and replace it with a bucket. Thereafter, Kaufman took to calling Fallingwater a “seven-bucket house”, referring to the seven buckets needed to catch all the drips any time it rained. It’s said, in fact, that so much moisture collected in one of the hallways that a drain had to be installed to get rid of it! Despite its flaws the Kaufmans remained deeply attached to their iconic home, able to enjoy the views and vistas through ample windows from its cozy interior while attempting to disregard its moisture challenges as best they could.

"And now the thickened sky like a dark ceiling stood; down rushed the rain impetuous" Milton

Le Corbusier, euro-modernist

With regard to Le Corbusier’s iconic modernist house, which predated Fallingwater by just a few years, things didn’t go nearly so well. Le Corbusier, who veered modernism towards extremism out of sheer contempt for prior building knowledge, systematically neglected water management at his infamous Villa Savoye, the first rendering of his belief that a house should be conceived as “a machine for living in.” Neither a gifted space planner nor concerned in any apparent way with human comfort, Le Corbusier achieved novelty in design by turning his back on the entire history of domestic architecture.

Despite a machine-like appearance and cold, sanitized d├ęcor that make it feel sealed off from the organic world, the flat-roofed Villa Savoye was an utter sieve from the day it was built. Set on stilts to remove it from the dampness of the earth, this elevated structure failed to respect the law of physics that oblige one to design and seal all exposed joints properly in order to keep water from infiltrating. In this regard, Villa Savoye was grossly deficient, indeed a total flop that would ultimately be abandoned by the couple it was built for! Like Fallingwater, Villa Savoye provided large outdoor spaces that simultaneously served as roofs for rooms beneath, with similar yet even more dire consequences.

Villa Savoye: like a gigantic appliance or an industrial air filtration unit, with strip windows

Indeed, so bad was Villa Savoye that its wealthy occupants complained bitterly to the architect about its failings from the outset: “It is raining in the hall, it’s raining on the ramp and the wall of the garage is absolutely soaked [….] it’s still raining in my bathroom, which floods in bad weather, as the water comes in through the skylight.”

Le Corb's ideal bog: a machine for washing in that flooded during rainfalls

Le Corbusier felt houses should be isolated as much as possible from the organic ground plane (rather the opposite of arts and crafts thinking) so he set his villa on pipe-stilts called ‘pilotis’. Architecturally, this contributed markedly to the building’s ungainly looks, making it appear like some sort of weird armature or a modular appliance of unknown purpose.

Austere living spaces lacking natural materials (no wood, fabric) with plate glass interior walls.

Shunning contact with the earth does not obviate the need to deal with weather effects – a truth le Corbusier simply chose to ignore (ignoring inconvenient realities seems a hallmark of both his urban planning and architectural ventures). He introduced vast areas of plate glass, which certainly allowed loads of light inside, but which also (because unventilated) caused the house to overheat badly in summer and (because uninsulated) caused it to be hard to heat in winter. Comfort was just not on his radar.

No sense of entry attempted or needed in this machine for living in!

Le Corbusier’s greatest failing however was his abject disregard of rain effects. It quickly became so uncomfortable living in the house that the owners sent him this curt note: “After innumerable demands you have finally accepted that this house which you built in 1929 is uninhabitable…. Please render it inhabitable immediately.”

Abandoned by its owners, commandeered by armies, left to molder prior to restoration

He ignored all these requests (of course), and shortly thereafter the owners abandoned the building on the grounds that it was defective beyond repair (they were also fleeing the blitz-kreiging Nazis). During the war, it was commandeered for military use and emerged abused and in semi-ruin. Le Corbusier himself would eventually go to bat for his prize dwelling, however, and succeeded in having it designated and restored as a monument to his personal greatness (or folly, depending on your point of view). Would-be modernists and gawkers visit it in droves every year.

The shroud signals a rotting exterior is being replaced

This indifference towards the invasive force of water continues in the minimalist camp of modernism to this very day. When contractors fabricate structures with poorly sealed stucco walls, metal framed windows lacking trim boards, exposed roof membranes, and eaves that don’t project over walls in buildings whose walls contain vapour barriers that prevent drying out – the net result is buildings that develop molds and begin to rot within a few years. We’ve seen a spate of this in condominiums and apartments over the past two decades here on our wet west coast (the phenomenon is described euphemistically as ‘premature building envelope failure’ PBEF). We don’t know how many families endure living in moldy environments as a result of PBEF, but it’s not a small number.

The basic idea of a gable roof is akin to that of an umbrella: a device for shedding water

The goal in all design and building is weather-tightness, though I would argue not air tightness, which bumps one right up against the ideology – oops, theory – of the modern vapour barrier. But that’s another matter for another time, perhaps. Fact is, at one hundred years of age, my bungalow remains dry and sound, sans flat roof, untrimmed windows, stucco walls or vapour barriers – and therefore it continues to serve as a truly comfortable house.

They may find dampness funny, but homeowners don't!