Top tips to optimally use conventional waterproofing techniques

While the first part of this two-part series examines conventional waterproofing systems and offers tips to use them for optimum effect, the second part will discuss modern waterproofing techniques. 

of building to prevent the ingress of water is an activity, which, perhaps is practiced in one form or the other, ever since the first building was built on earth. The methodology has been changing with the changes in the architectural designs and with the availability different building materials in construction.
 
In the initial stages when stone was the main building placed in position with mud or lime mortar the emphasis used to be to make the construction in such a way that the rainwater does not collect on the roofs. Hence old relied mainly on dome structures or slanting roofs. The slow speed of such construction and unaffordability of common man to build such structures for their own dwelling, made constant evolution and development in the technology.


 
With these developments the concepts of also changed. Now in present day construction wherein the ordinary and its blends with and slag materials has come to stay a lot of compatible alternatives are available for a builder to choose from various systems. Some systems are old and conventional but still practiced successfully and some are modern systems designed taking the material and structural behaviour into consideration.
 
There are some compounds, which are used in plastic concrete to make it less permeable to water. These compounds are known as integral compounds. They are based on plasticising and air-entrainment or water repellence principles. These are used as a good precautions when other factors such as good mix-design, proper mixing/placing, compacting/curing etc are taken care of. This subject of integral compounds requires in depth discussion hence will not be taken up here. Similarly there are some water proofing techniques for vertical surfaces. These techniques are also used for preserving heritage buildings by stopping/minimising the aging process of these buildings.
 
For solving water seepage problems, customers use both conventional as well as modern techniques.
 
Some of the old and conventional systems are as follows:


This system was developed during the initial stages of flat roof construction with lime mortar burnt clay brick pieces. This system involved laying lightweight mortar on the roof and spreading it to give gentle slopes for draining away the rainwater immediately. The mortar consisted of lightweight brick pieces as aggregates and ground brick with lime as binding matrix.
 
During British rule this system became more popular not because of its efficiency but because of its efficiency in keeping the interiors cool. Some applicators developed better skills in laying these systems, with neatly finished top with lines engraved on top of plastic mortar now known as IPS. Some practiced embedding broken tile or ceramic pieces in the plastic mortar and called it china mosaic.
 
This type of system remained most popular with multi-storeyed construction in all major cities. The system lasts up to 15 years if done by skilful applicators. This system may be considered more from its weather proofing abilities rather than its qualities. Once water starts entering into the brickbat coba the brick pieces absorb too much of water and the roof becomes an invisible pond of water continuously causing leakage and increasing burden on the roof slab. It will be highly beneficial if brick-bat coba is laid on a flexible membrane as water proofing as well as economical weather proofing can be achieved with this system.
 
treatment
Discovery of petroleum and its products and by-products has given the construction industry an indispensable product in the form of bitumen. Bitumen is more commonly used in the form of felt or flexible membrane formed by sandwiching jute fabric or fibreglass/polypropylene mats with chemically modified bitumen. These membranes are laid on the roofing over a bitumen primer. There are two types of membranes one is cold applied and the other hot applied which means one needs to heat the edges of the felt with a torch so that they melt and stick to the second layer in the overlap area.
 
On the roofs the bitumen felts have not been successful because of the unacceptable black appearance and inaccessibility of the terrace for other social uses. Technically it is not preferred because bitumen layer or felt on the terrace not only makes it watertight but also airtight. Concrete has the breathing property. It takes water/moisture and breathes out water vapour. Hindrance of this breathing property of concrete develops pore pressure, which causes blisters in the felt.
 
After a few seasons the blisters multiply and eventually delaminate the felt from the concrete surface. Hindrance of breathing property of concrete makes the concrete weak. But on the asbestos sheets and zinc sheets in factory roofs, this bitumen felt is the only dependable system. Hence all factory roofs in India adopt this water proofing system.
 
Bitumen is very effective in of basements from outside. Bitumen primers have very successfully been used as damp-proof course in earlier days. This practice is slowly discontinued for whatever reasons now very few engineers now believe that this was in practice once. As consequence of this absent DPC we have a lot of cases of rising dampness, which we tend to attribute to wrong reasons such as the quality or salinity of sand etc. Bitumen still is the product of first choice where it is commonly recommended, in areas such as industrial roof waterproofing, basement waterproofing, and damp-proof course. More over bitumen is the most economical product available for   
    
Metallic sheet wrapping
Because of the non-existence of suitable expansion joint filling compounds before the discovery of poly-sulphides, a complex procedure used to be adopted to treat expansion joints, in concrete dams and such huge structures utilising thick copper sheets. An extension of this practice was to try thin foils of copper and aluminium for wrapping the concrete surfaces with nagging leakage problems.
 
Unavailability of common joining material for these metal foils and the concrete and mortar created weakness in the system at the joints. This discouraged the system in its infancy only. But there after the metal manufacturers have been trying to market this type of system with improved adhesives as and when the metal market slumped.
 
based treatment
consists of two liquid components one is called the base component and the other is called reactor or curing agent. Base is a polyol and the reactor is an isocyanide such as TDI or MDI. There are various grades of and so also there are numerous isocyanides. The combination of these two ingredients results in a formation liquid applied rigid membrane or a foam depending upon the selection.
 
In waterproofing, this rigid liquid membrane was tried with fibreglass reinforcing mats. The systems failed because coefficients of thermal expansion of concrete and rigid PU membrane being different lateral movement or creep occurred with the passage on one working climatic cycle. When exposed to ultra violet rays or direct sunlight most rigid membranes became brittle and crumbled.
 
Apart from this the application of coating needed very rigorous surface preparation. The surface needed to be neutralised by removing alkalinity from the concrete surface through acid itching then washing and blowtorching to make the surface bone dry. This kind of surface preparation with acids angered the civil engineering community and the product ceased to be used as material apart from its several failures. Never the less continuous research in the technology gave the construction industry excellent sealant for glazing industry and foams for thermal insulations. The new generation polyurethanes, which are alkali stable and water-based, may find better applications in industry.
 
based system
Like is also a two-component system having a base resin and a reactor or curing agent. Base resin is obtained by dissolving bis-phenol A flakes in epichlorohydrin. This base is available in various viscosity ranges to suit different application conditions. The curing agent is an amine/polyamine aliphatic or aromatic, or an amine-adduct for general applications and polyamide or an amino-amide for coating purposes. After mixing base and reactor components the resultant viscous liquid or paste if some fillers are added to it can be brush applied like a paint or trowel applied like a mortar.
 
Here also epoxies not withstanding the alkalinity of concrete and the concrete needs to be acid washed and neutralised, which the civil engineers hated. Here again the coefficient of thermal expansion of concrete and being different the compatibility of in exposed concrete surfaces such as roofs became limited. Later the use of in was discarded. But epoxies have come to stay in civil engineering industry as bonding agents, floor & wall coatings, coatings for food processing units, operation theatres and computer and pharmaceutical industries.
 
Box type waterproofing
This type of water proofing system is used only for basement or structures below the ground level from outside to prevent leakages of subsoil water into the basement.
 
In this method, limestone slabs (Shahabad Stones) are first laid in the excavated pit over blinding concrete in a staggered joint fashion to avoid the continuity of the mortar joints. The joints are effectively filled with rich mortar admixed with integral compound and cured. Over this the raft is laid and shear/brick walls constructed. The limestone slabs are erected around the walls in a similar fashion leaving a gap of one to two inches between the external surface of the wall and the inner face of the stone surface. The joints again effectively sealed with rich admixed mortar and the same mortar is filled in the gap between the wall and the stones. This stonework is continued up to ground level. In this system the raft and the sidewalls are protected from direct exposure to sub soil water.
 
This system works on two principles of common sense. First, the area exposed to subsoil water is only the area of the joint where as the whole stone is impervious to water, hence only a fraction of area, that is, that of the joint is exposed to subsoil water, when the joint itself is filled with rich and quality mortar. Second, the path of water to reach the raft or the sidewall is elongated. This elongated path is through quality mortar. This system seeks to delay the occurrence of leakages in the basements. A lot of building structures are waterproofed by this system. A few notable successes are to its credit especially in five star hotels and of-course there are a few failures as well.
 
(The second part of this series will discuss the modern techniques and their advantages)

 This post was taken from http://www.business-standard.com

6 tips to help you tackle damp problems in your home

Damp plaster is unpleasant to live with, especially at this time of year, and can affect the whole room, but what can you do about it?

Here are six tips for dealing with the problem:

1. Check the outside of your home. Penetrating damp happens when there's a problem with the fabric of the building. While the damp usually moves horizontally from the outside in, it can appear on ceilings (see below) as well as walls.

Defective or missing flashing on the roof, defective or blocked guttering, defective pointing and brickwork, and cracked or missing render typically cause penetrating damp, although there may be other causes. Sometimes what appears to be damp may actually be condensation.

2. If the lower part of a wall is damp, it's probably rising damp (water coming up from the ground), in which case the solution may be a new damp-proof course, installed by a specialist damp company (other damp-proofing solutions are available).

Once the bricks are damp, the moisture usually transfers to the plaster inside - tell-tale signs include dark patches and blistering/bubbling paint, but it's not always obvious that the plaster is damp. Damp plaster should be removed to expose the bricks underneath - letting them dry out is a good idea, but it can take a very long time.

3. If you can't wait, get a plasterer to do a waterproof render and then replaster, so there's a barrier between the moisture in the bricks and the new plaster. This is a messy process and if you get a specialist damp company to do it, it may be expensive, but they should provide a guarantee. Most plasterers won't give you a guarantee, but should charge a lot less.

The key is to get an experienced and reputable plasterer who knows what they're doing and uses the right products. If the waterproof render isn't done correctly, the damp will come back through the plaster, which is disastrous.

4. Sometimes the damp-proof course is simply being prevented from doing its job. You should be able to see it along your home's exterior walls - look for a row of small holes a little way up from the ground.

In old properties, slate was used as the original damp-proof course and is sometimes still in place. If the level of your garden, patio or path is higher than the damp-proof course, for example, it won't work properly.

5. Perhaps you've noticed damp on a chimney breast, or where the chimney breast would have originally been? This could be because the chimney stack needs repairs, the chimney pot isn't capped, or the chimney breast isn't ventilated properly indoors.

When a fireplace opening is sealed up, a vent should be fitted, but isn't always (it's a relatively straightforward DIY job to fit one), and vents can get blocked with dust and debris. A defective chimney or roof can cause damp on the ceilings below, especially if there's no roofing felt, which is sometimes the case in old properties.

6. The quickest and easiest DIY way to deal with damp plaster is to cover it with anti-damp paint and then repaint the topcoat. Anti-damp paint is usually really thick, so apply it with a brush (to get lots on) and then use a mini foam roller to get a good, flat finish. Leave it to dry thoroughly - see the manufacturer's instructions - and apply a second coat if recommended.

Anti-damp paint works well for a while, but is rarely able to hold back damp long term.

Our RapidGuard product will prevent moisture from penetrating the surface. Read more here.

This post was taken from www.newsshopper.co.uk

How are roofing costs estimated?

General Tips

The roof is one of the biggest investments you'll make in your home. Find out how the costs of installation of a new roof and repairs on existing roofs are determined.

Size: Roofers will calculate the exact size and dimensions of your roof to best estimate the amount of materials needed.

Slope of your roof: The steeper your roof is, the more materials will be needed to cover it.

Materials: The price for materials will depend on what kind of roofing materials you choose to have installed.

Roof access: If your roof is difficult to access, or if it is multiple stories, contractors may charge more.

Difficulty level: If your project is complex - for example, if you have chimneys, skylights and vents that roofers need to work around - the higher the cost could be.

Location: Where you live could determine your estimate.

See this article here & credit goes to http://www.news8000.com/lifestyle/how-are-roofing-costs-estimated/221573408

local.which.co.uk contacted Which? Local-recommended traders to find out how much standard jobs should cost and how quickly they should be completed. Armed with this information, you’ll feel confident about hiring traders and be better equipped to spot when things aren't right.

local.which.co.uk surveyed recommended roofers to find out how much you should spend on 13 common jobs and how long they should take to complete.

How are roofing costs estimated? roof 1197886 1920

Trader tip: scaffolding

If extensive work is taking place on a property above one storey high then it’s likely that scaffolding will be required.

Scaffolding is expensive, and takes hours to put up and take down. This will increase the price of quotes.

Research methodology

In July 2012, we sent a survey to all Which? Local traders in the Roofers category with a rating of three stars or more and an email address.

20 roofing professionals responded to the survey. Using their experience and expertise, they answered questions about the cost of popular roofing jobs, and how long they should take to complete.

Job Details Typical price quoted Price range Typical time to complete job
Survey conducted in July 2012
Replace fascias and soffits on a typical three-bed detached bungalow Remove wooden fascias and soffits. Replace with uVPC. Includes cost of labour and materials. Assuming no scaffolding needed. £1,900 £1,250-£2,225 2–5 days
Replace fascias and soffits on a typical three-bed detached, two-storey house Remove wooden fascias and soffits. Replace with uVPC. Includes cost of labour, materials and scaffolding. £2,425 £1,625-£3,000 2–5 days
Replace lead flashing on chimney n/a £340 £300-£450 1 day
Fix leaking roof on a two-bed bungalow Replace approx six roof tiles. n/a £80-£189 1-3 hours
Fix leaking roof on three-bed, semi-detached, two storey house Replace approx six roof tiles. n/a £88-£200 1–3 hours
Replace whole roof on a two-bed bungalow – plain tiles Remove existing tiles, fit new plain tiles. Includes cost of labour, materials and scaffolding. £4,500 £3,850-£5,875 4-6 days
Replace whole roof on a three-bed, semi-detached, two-storey house – plain tiles Remove existing tiles, fit new plain tiles. Includes cost of labour and materials. £5,600 £4,500-£7,000 6–10 days
Replace whole roof on a four-bed, detached, two-storey house – plain tiles Remove existing tiles, fit new plain tiles. Includes cost of labour and materials. £6,750 £5,500-£8,750 10–14 days
Replace whole roof on a two-bed bungalow - slate Remove existing slate and replace with new. £4,800 £4,000-£6,000 5–10 days
Replace whole roof on a three-bed, semi-detached, two-storey house – slate Remove existing slate and replace with new. £6,250 £5,000-£7,500 8–12 days
Replace whole roof on a four-bed, detached, two-storey house – slate Remove existing slate and replace with new. £8,250 £6,500-£12,000 10–20 days
Flat roof on typical single garage Put a flat roof on existing single garage - rubber membrane. £900 £840-£1,150 1 day
Flat roof on conservatory Put a flat roof on a conservatory measuring approx 10'10” x      

This has been taken from https://local.which.co.uk/advice/cost-price-information-roofers-roofing-jobs

Tips on preparing your roof for winter

Tips on preparing your roof for winter

INSPECT THE ROOF

Some people love the sound of rain, but nobody likes the drip, drip, drip of a leaky roof. So start your fall home inspection from the top, taking a good look at the condition of your roof. Curled, damaged, loose or missing shingles are signs that your roof may be compromised.

"Problems can arise anywhere on the roof, but more often than not, the best areas to check are generally where shingles meet any wall, chimney, skylight, pipe or other flashings," said Jeff Durocher, of Jeff Durocher Roofing in Little Falls.

A loose shingle doesn’t seem like much cause for concern, but it can lead to bigger problems. As Durocher noted, "if it blows off, becomes damaged in a storm or if there is a few feet of snow on the roof, the result can be a serious leak.Sometimes problems won’t be seen until expensive interior damage is already done. This makes what would have typically been a simple maintenance repair job much more invasive, requiring tearing up an area of roofing and removing and replacing rotted wood from scratch."

Before climbing a ladder to check out the conditions on the roof yourself, however, consider that a thorough inspection should really be left to a pro. "Some people may be tempted, but if your shingles are sliding out of place in one area, who is to say others won’t slide out from under your feet when you’re attempting a repair," cautioned Durocher. "Plus sometimes what looks like a small problem, can really be much worse. A professional may notice things that a homeowner cannot."

Although he doesn’t recommend leaving a roof inspection to a do-it-yourselfer, Durocher said you can also check inside your home for telltale signs of trouble. He recommends examining the ceiling for stains. Water stains usually have a dark ring around them and get larger and darker after it rains. Take particular note of what Durocher called "flashing regions," the walls and ceiling around skylights or chimneys.

DODGE THE DRAFT

Here’s one way to keep your heating bills low: seal leaks due to cracks around your home’s windows and doors. Weather stripping is an inexpensive solution, but it can deter-iorate, so check it and replace it if necessary.

Caulk is another easy remedy for drafty gaps not only around doors and windows, but for places on an exterior wall where cable, phone, electrical or gas lines enter the house. If there is existing caulk, make sure it isn’t cracked or damaged. If it is, scrape off the old stuff and re-caulk.

Test for drafts in all of these areas on a windy day now, and take appropriate measures before the temperature drops to freezing.

CHECK STAIRS, WALKWAYS, DRIVEWAYS

Chipped stairs and loose railings spell potential disaster, as do damaged walkways and driveways. And the danger is exacerbated when conditions outdoors are slippery and icy. Minor repairs to concrete surfaces are easy, however.

Clean out the crack thoroughly, using a wire brush. Then apply a concrete repair caulk or crack filler, which you can find in any home improvement or hardware store. You can also find patch kits for driveways, working the same way. But leave major repairs to large cracks, stairs and other concrete surfaces to a professional.

Finally, a few last words to the wise from Durocher, "A homeowner should look at their property before the bad winter weather comes and always look as often as possible. There may be problems a professional contractor can correct with simple standard maintenance. Being proactive with your property will go a long way in making sure your home is prepared for the most crucial months of the year."

This was taken from blog post http://archive.northjersey.com/

Tips on preparing your roof for winter Tips on preparing your roof for winter snow 941411 1920

CLEAN THE GUTTERS

Right now falling leaves, twigs and other wind-blown debris are not just covering your lawn, they are clogging your gutters and drain spouts. Cleaning the gutters is a minor task but it’s of major importance.

Said Tom Stachelrodt of North Jersey Gutter Topper in Ridgewood, "Clogged gutters in the winter prevent rain and melting snow from flowing away from your house, causing snow and ice buildup on your roof and gutters. This extra weight can result in gutters that pull away from or fall off the house. It also causes ice damming, which is a buildup of melting snow and ice that can [leak into] your home."

Clean, unobstructed gutters, on the other hand, head off potential water damage to the roof and also to siding and even your home’s foundation.

Cleaning the gutters yourself is relatively easy. You’ll need a trowel, or work gloves, to scoop out twigs, leaves, dirt or any other bits of things — including insects and other critters that may be nesting in there.

You’ll also need a sturdy ladder. Never stand on the roof and lean over to do the job. That’s dangerous.

Once you’ve cleaned out everything, flush the gutters with water, using a garden hose. Then make sure the downspouts are clear and nothing is lodging inside them.

However, Stachelrodt cautioned, "Cleaning your gutters once or twice a year does not guarantee clean gutters. You should clean them at least six times a year to ensure the flow of water away from the house."

You might consider installing gutter screens or gutter guards. A gutter guard is a product made of aluminum or super-fine mesh screening or perforated metal that goes over the existing gutter or it can be a heavy-duty brush that sits inside the gutter to prevent clogs [resulting] from the buildup of leaves and other debris.

Roof Protection 6 tips

6 Guided Tips For Roof Protection and Repair Tips

What indicates holes in flashing?

Holes in Flashing

Rainwater will penetrate wherever there's an opening, and there are a lot more than the average person realizes. Check out the underside of the roof for wetness or mold around points of penetration (plumbing vents, chimneys), wherever different roof planes intersect (valleys) and near dormers. *These are signs you've got holes in your flashing or that the flashing was installed wrong.

Flashing refers to thin pieces of impervious material installed to prevent the passage of water into a structure from a joint or as part of a weather resistant barrier (WRB) system.

 

How can I tell if my roofing material is defective?

Once rainwater breaks into your house, it can be very elusive. You may not find water directly below a penetration point. Keep in mind that water may travel sideways before passing through a joint in the roof sheathing, and may travel in a horizontal joint before falling on the floor or ceiling. If this happens, there may be a problem in the roofing material.

 

How much water does a roof collect in a 2 inch rainfall?

Of Roofs and Rainfall

One very obvious source of moisture and/or water in your basement is rainwater. During a hard 2 "- rainfall, a 1,000-square-foot roof will collect about 250 gallons of water, dying to get into you nice dry basement. If you have four downspouts, that averages out to about 63 gallons (240 l) per downspout location. Check your roof thoroughly for leaks and repair them as soon as possible. The longer you let the problem occur, the worse the damage will be.

 

What are the most common sources of a leaky roof?

Common Sources of Roof Leaks

Every time it rains, your roof is under attack from liquid invaders from the sky, seeking to breech your home's defenses and steal your right to be warm and dry (well, that's one way of looking at it). Rainwater is quick to exploit any weakness in the integrity of your roofing defense system. Roofing materials can wear out, break, rust, blow off, or otherwise fail and give moisture the opening it needs to do its damage. Most commonly rainwater finds its way through the roof by way of a chimney, plumbing vent, exhaust fan or skylight, flashings when the sealant joints around these penetrations crack and fail. Look for potential chinks in your home's armor in the following areas:

  • Old or defective shingles can curl and crack, allowing moisture intrusion. If old shingles aren't removed before new roof shingles are applied, it can reduce the life of the new roof. 
    • Chimney caps can crack allowing water inside the chimney. 
    • Gutter flashing can fail, forcing rainwater to set up camp between the roof and gutter. 
    • Flat or low pitched roofs have unique maintenance needs and are susceptible to water problems because they may not drain as quickly as roofs with a steeper pitch.

Flat roof drains or scuppers can clog and hold water on the roof, increasing the risk, not only of a leak, but of a possible collapse of the entire roof under the weight of the water. The price of dryness is eternal vigilance. Keep possible penetration points well sealed and maintained and you will have nothing to fear from raindrops falling on your roof. You don't need a guide to roof protection and repair to know that prevention is your best defense.

Where do I start looking for a leak.

 

Locating a Roof Leak

When it comes to leaking roofs, many homeowners are looking for leaks in all the wrong places. You no longer have to be one of them. The first and perhaps most obvious place to look for a roof leak is directly above the leak in a ceiling or exterior wall. Use a flashlight to inspect the attic floor over the leak while it's raining. If you see standing water, water stains, mold, wet insulation or other exposed insulation, you've found what you've been looking for.

What do I do about a leaky roof?

 

Preventing Roof Leak Damage

A leaky roof can be a pain forever, if not taken care of promptly. As soon as you spot water coming in, stains, or mold, take immediate action to limit damage. Hire a professional to nip it in the bud or go to the library and pick up a guide to roof protection and repair so you can handle it yourself. Locate the leak from inside and then take steps to control the damage until you can have a suitable outside inspection and repair done. Remember, your leaky roof won't get better with age and won't repair itself.

Written by: LifeTips link to blog post below.

Life Tips