Flat Roof Design

Flat Roof Design

How a Warm Roof Construction Can Benefit Your Home and Wallet!

Flat roofs traditionally consisted of a timber deck with a waterproof covering on top. It’s a very old (and many would agree, outmoded) structure form dating back many years. If insulation was provided at all, it was frequently considered something of an afterthought and generally comprised mineral wool stuffed between the rafters or joists.

Without sufficient ventilation, this type of arrangement can be rendered ineffective and can cause condensation, leading to rotting timbers and damp ceilings. If this type of ‘cold’ roof is to be efficient at all, then good ventilation is essential. Particularly in roof spaces above areas renowned for a build up of moisture, such as kitchens and bathrooms.

The downside to ‘vented’ fascia boards or roofing vents is that a great deal of heat is lost in the process of allowing condensation to escape. Your heating literally goes through the roof, along with your heating costs!

A similar process occurs with a cold pitched roof. Introducing ventilation into pitched roofs can promote warm air leakage from your property into the roof space, creating excess moisture into the construction. It can also provide a breeding ground for dirt, dust and insects.

At one time, these ‘ventilation’ processes may well have been enough to satisfy building regulations, but nowadays, from an energy conservation perspective, this is not sound practice at all.

Far from it.

How To Create A Breathable Roof Construction – A Warm Roof Construction

So a roof that was ventilated satisfied the building regulations but as you can imagine it also increased heatloss.

So what is the alternative?

To create a construction that is ‘breathable’ yet prevents air and moisture from becoming trapped, which can lead to the decay of the building. The solution is to employ a ‘warm roof construction.’

Unlike the problems associated with a cold flat or pitched roof, a warm roof construction enables you to conserve the heat within your property – no ventilation required.

So how does it work?

Well, the insulation is effectively moved to the outside of your roof structure, removing the possibility for condensation to form on the underside on the deck and therefore eliminating the capacity for damp.

So when constructing a warm roof the insulation is laid across the rafters and then the battens are fixed above the insulation and then the tiles fixed to the battens.

A warm roof will keep the whole family snug and cozy in winter and comfortably cool during the warmer months. Plus, your home will be rendered thermally-efficient, benefitting from improved heating and cooling costs.

As you have seen, a warm roof construction will benefit your living experience in several ways. As well as residing in more comfortable surroundings, conserving optimum heat means that savings will be reflected in your quarterly bills.

What are your main priorities when you come to install a roof?

What are your main priorities when you come to install a roof? Is it energy efficiency, cost, warmth – or do you simply want to keep the rain out? The kind of roof you choose will be dictated by your priorities and also to a certain extent by the type of structure you are building. Today warm roof construction is generally the most popular option, but cold roofs have certainly been around longer and also have many things to recommend them.

One obvious benefit of warm roof construction for domestic purposes is that its insulation is on the outside of the structure, so the decking within is kept warm. With a cold roof, the waterproofing is laid directly onto the decking so the only place for insulation is between the ceiling joists. This creates two opposing temperatures within the roof which can cause condensation as well as a certain amount of heat loss.

With the warm roof, where there are not two opposing temperatures, condensation is avoided. Through ventilation can be used in cold roofs in some cases to reduce this risk, but this can be difficult to achieve, for example if the roof abuts the house.

In terms of energy efficiency, warm roofs are probably the best choice for new-build projects. Because there is less of an issue with condensation this also means there is no need for ventilation which significantly reduces the amount of energy needed to heat a building. With cold roofs, voids are needed underneath roof tiles in order for the condensation to dissipate and this means a great deal of heat can be lost.

Warm roofs are also able to incorporate modern polyisocyanurate (PIR) rigid foam insulation as there are no depth limitations to be considered. With cold roofs, because as mentioned above there is only a limited space for insulation around the ceiling joists, glass mineral wool insulation is used instead. Whilst this has been sufficient in the past, the need for ventilation means it is not as efficient as the newer, rigid forms of insulation.

Cold roof construction is certainly the cheaper option all-told, but the higher costs of warm roof construction can be easily set off by the cost and energy saving benefits – and this is true for both flat and pitched roofs. All-in-all, this does seem to be the more efficient method and its popularity can only continue to grow as insulation technology improves further.

Cold roof construction is the older roofing method and is still used today in certain circumstances. However, warm roof construction is certainly proving the most popular nowadays from an efficiency perspective.

Tiling Low Pitch Roofs

Type ‘low pitch roof’ into your favorite search engine and you’ll run headlong into forum after forum of the problems and hassle low pitch roofs can (and have) caused roofers, builders and such like. Building regulations are often the first obstacle someone wanting to put a low pitch roof onto their home or extension will come across, although there are a number of issues with low pitched roofs.

Naturally, a roof should reflect the climate in which the building stands although there aren’t many limitations on the actual pitch of a roof in the UK according to James Roofing Services. There are, however, building regulations that stipulate which materials can be used for any given pitch. In addition, regulations will determine the spans and spacing required between rafters for a certain pitch of roof. The first thing to ensure before building an extension, is that the plan for the roof meets the local Building Control regulations as guidelines can between local authorities. Local authorities in places with high annual snow fall require steep pitches, for obvious reasons!

Low pitch roofs require specialist low pitch roof tiles, which aren’t all that easy to come by. Anything under 15° will be difficult to tile, and in all honesty, may well be unsuitable for tiling anyway. Wind driven rain is the main problem with low pitch roof tiles. Even if the roof is well protected beneath the tiles with felt and suchlike, the wind can rifle through the tiles, forcing them to vibrate and cause a chattering effect. If there isn’t adequate protection underneath the tiles, the consequences can be severe damp and leakages!

As a general rule of thumb any pitch below 30° is too low for plain tiles. Any pitch lower than 17.5° is too low for slate tiles and concrete tiles will suffice down to about 15°.There are some low pitch roof tiles out there, however, with some companies offering tiles suitable for pitches as low as 10°.

The Green Roof Tile Company offers a great solution to problem of low pitch roofs. Their Envirotile is suitable for pitches as low as 12.5° and are also very environmentally friendly. Their lightweight, robust design means carbon emissions are considerably lower for transporting the tiles when compared to traditionally slate. In addition, the Envirotiles are made of recycled material that would otherwise end up rotting in landfill!

Tiles, of course, aren’t the only solution to low pitch roof problems. Corrugate metal or ply and felt solutions can be more than adequate, particularly on garages or outhouses.

If you are desperate for a tiled effect, you may be advised to apply a ply and felt solution and then tile over the top. The tiles will of course be purely for decoration but be warned, there are risks with such a method. Some builders will advise avoiding this completely as the roof battens are prone to rotting due to constant damp and the felt is almost unavoidably punctured by the tile nails. Whilst there are of course ways around these problems, inexperienced roofers should probably heed this advice! Talk to a professional and the building regulations to be certain your solution is legal and credible.

To conclude, with careful planning there is no reason why you can’t tile a low pitched roof. With careful consideration for regulation and the climate, the risk of damp or damage to a building can be limited to an acceptable level but be sure to consult the professionals if you are in any doubt.

Common Problems & Solutions

Flat roofing is a most common type of roofing being installed on living property. It is more popular in snowy and rainy areas. Flat roofing is economical and simple, that is why more popular, yet it is also not free with some common issues. Following are the common problems attached with Flat roofing solutions.

Common Flat Roofing Problems and its Solutions:

– It is important to inspect flat roofs for snow buildup. Snow and ice normally block the drains and gutters during cold weather, which ultimately allow water to puddle on the surface of roof. In this situation, first step is to remove excess water from building roof. Standing water can be rid of by using squeegee, broom or shovel.

– In case the standing water is not properly redirected or drains are not cleared, the property may develop a serious roof leak which caused damage of attic insulation, flooring and indoor furnishings.

– Cracks in the sheathing or outer layer of roof also a reason for many flat roof leak. The basic caused may be material irregularities. If a crack is encountered during roof inspection, cover the surrounding of the affected area so that the moister could dry then apply high quality roofing cement into the cracked area. Apply two to three layers of cement if needed to ensure the optimal coverage and future leak prevention. After the completion of repairing work, test the repaired area with the help of garden hose. Before testing the repaired area, make sure it is dried.

– Roof leak because of flashing damage can be the cause of growth of fungus on roof. Moisture in problem areas allow fungus to grow and it also push away the shingles and flashing on roof. In such situation, first wear work gloves and safety mask to avoid fungus inhalation. Then apply the roofing fungicide at the point of leak. Multiple fungicide treatment may be required to use if buildup is severe. It is suggested to purchase a flashing repair kit. The kit provides number of detailed instructions to overcome all sealing and repairing problems.

Following precautions are helpful to avoid roofing problems.

– At the time of roof installation, make sure that the roofer has relevant experience, skills and insurance to carry out the work properly. Check the references and ask about the previous work, it will be helpful to avoid poor quality roofing problem after construction.

– At the time of designing stage, detailing is very important. A common area which joint between the flat roof and any parapet wall need to be properly designed and build. A minor mistake at the planning phase could cause break in the waterproofing covering of roof or parapet wall.

With all above mentioned problems, the popularity of flat roofing cannot be denied. The best approach to avoid damage issues is to select an experienced construction company. It will be helpful to not only get the quality roofing service but also the best return of investment in longer run.

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