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Tear Off
Tearing off an old roof doesn't take a lot of special skill. Basically, you just pry up the shingles using a pitchfork or shovel. Before you begin a tear off, protect trees and shrubs near the house by leaning up plywood sheets.
Locate a construction dumpster, pickup, truck or other container close to the roof. Toss the shingles directly into the container to save from having to pick them up later and to prevent nails from getting lost in the lawn. You may even want to build a temporary chute to funnel shingles into the container. If you're using a pickup or trailer, be careful not to overload it.
Pull up any exposed nails instead of pounding them down. Otherwise, they may work back up. Replace any damaged or missing sheathing, fascia or soffits. We used plywood, but oriented strand board is a good substitute.
It's often difficult to judge how long shingling may take. Of course, the best option is to only tear off as much as can be replaced before bad weather hits. But, you may want to fasten temporary tarps at the roof peaks in case of rain or unpredictable weather.
It's always a good idea to pick up stray nails on the ground at some time during the project. However. since the roof is now exposed, time and weather conditions become important factors. So, it's usually best to do that last or as soon as the roof has underlayment.
Underlayment & Flashing
In most areas of the country, a roof can't withstand exposure to the elements with just a layer of shingles to protect it. An additional underlayment layer(s) is needed to deter water penetration.
Properly sealing out water before shingling requires these elements:
Laying A Waterproofing Membrane
Rolling Out Builder's Felt
Installing Flashing
Fastening Drip Edges
--------------------------------------------------------------------------------
Laying A Waterproofing Membrane
Start by adding a waterproofing membrane along eaves and valleys. These are high-risk areas for leaks; valleys due to improper flashing installation and eaves because of ice dams. We used a thick, bituminous material with an adhesive backing.
The membrane protection provides extra protection against water penetration and is also required by code in "Snow Belt" states at the eaves.
Waterproofing membrane material can be considerably more expensive than just using felt. Most professional roofers recommend the extra protection, and for a do-it-yourselfer, it's good insurance against a leaky roof.
Rolling Out Builder's Felt
Builder's felt (tar paper) is the most widely used roofing underlayment. It comes in rolls and its thickness is gauged in pounds. Typically, a roll of 15 lb. felt may cover about 400 sq. ft. and a roll of 30lb. would cover half that area.
Laying felt is much easier and faster with two people; one rolling, one stapling/nailing. Position the felt roll flush with the gable end.
Working toward the far end or valley, unroll about 5' of felt, square it with the roof edges, press out any wrinkles, and staple/nail it in place as you go. Proceed at 5' intervals to the far end. When you run into a valley, angle cut the felt to lie down the middle of the valley. If you forego the membrane, lay down extra felt at the valleys.
Overlap the second row of felt on the first row by 2". Work up the roof this way to the ridge (peak). Leave the ridge exposed and continue underlayment on the other side. When you reach the ridge, fold the felt over both sides (overlapping 2") and fasten it into position.
Once the roof has underlayment, it can withstand exposure for a few days. However, if it gets wet, the felt may wrinkle up a bit and that increases its chances of tearing by wind.
Installing Flashing
In some cases, metal flashing can be saved and reused during a tear off. But any flashing that is bent, torn or looks bad should be replaced, instead of repaired.
One type of flashing we recommend is galvanized steel, W-shaped valley flashing. It fits in the valley like typical "V" flashing, but has a small ridge sticking up in the middle. This ridge prevents runoff rain from running down one side of the roof and splashing up under shingles on the opposing side.
Set the flashing flush with the drip edges at the bottom of the valley, trimming it with tin snips if necessary. Nail the flashing every 1' or so near its outside edges (never nail in or near the middle). For extra protection, seal seams between pieces and all nailheads with roofing cement.
Fastening Drip Edges
Drip edges are corner-shaped metal strips that nail along the edges of the roof. They allow water from the roof to run cleanly off the edge. Without a drip edge, water may run down the side of the fascia and siding -- causing stains and eventual damage. The drip edge also supports the part of the shingle that extends past the decking.
Along the eave, nail the drip edge under the builder's felt and over the fascia. As an extra precaution, you may want to cover the nailheads with roofing cement then stick the felt down.
At the rake (overhang), install the drip edge over the felt and fascia. This protects the felt from high winds and blowing rain.
NOTE: The length of eaves and rakes may require using more than one piece of drip edge. Like flashing, lap upper pieces over lower pieces.
Shingling
Shingling is a notoriously hot and exhausting job, and working alone is a chore for anyone. It's usually easier, faster and safer to work with a partner. Also, renting a compressor and pneumatic nailer/stapler is money well spent on a big project.
WARNING: Working on a roof is always dangerous. If you feel uncomfortable or unsure about working on the roof, don't. Hire someone to do the work for you.
How Many Shingles?
Getting Straight Lines
Laying The First Courses
Racking Shingles
Using Roof Jacks
Safety Issues and Tips
--------------------------------------------------------------------------------
How Many Shingles?
The surface area of a roof is measured in "squares" of shingles. Each square covers 100 square feet. However, when you buy shingles, they're usually priced per bundle.
Calculate the number of bundles needed by measuring the roof's square footage (length X width). Divide that number by 100 to get the number of squares needed. Multiply the number of squares by 3 (in most cases) or the number of bundles it takes to equal one square. Again, in most cases 3 bundles = 1 square.
Getting Straight Lines
Throughout the shingling process, a sure-fire way to get straight lines and make a roofing job look professional is to snap chalklines.
An experienced roofer may be able to just butt the next shingle square with the previous one, but getting them all straight takes some practice and never guarantees straight lines. So we encourage you to take a few extra minutes and snap some chalklines for key areas.
A horizontal line across the starter strip to guide the top of the first row.
After the first course of shingles is laid, snap a vertical line the height of the roof to indicate the inside edge of the first shingle. This mark will be a guideline for the first shingle in the 3rd, 5th, 7th, etc. rows.
After the second course is laid, snap a vertical chalkline to indicate the inside edge of the second row's first shingle. This mark is the guideline for the 2nd, 4th, 6th, etc. rows.
Laying The First Courses
Lay a starter strip before the first full course of shingles. The starter strip consists of "tabless" shingles that you can make by cutting the tabs from regular shingles. To discourage water penetration, stagger the starter joints from the first course joints.
Shingling methods tends to vary. One person may start with a full shingle on the first row and cut a shingle to fit at the end -- depending on the roof distance. Sometimes, this method creates a tiny 1" to 3" piece at the end. So it's best to measure the length of a full shingle (usually 36") and divide it into the length of the roof (in inches) to figure how the shingles will lay out.
If you want the shingle to overhang (ours extended 1/4"), that factors into the length. That required us to precut the end shingles before nailing them.
In other cases, you may be able to let the first shingle run wild, cut it flush and use that "scrap" piece on the opposing end to complete the row. Again, how you start each row depends on the shingle and roof lengths.
Nail the first course of shingles at each end and middle tabs about 1/2" to 5/8" above the tabs.
Stagger the first shingle of the second course 6" short of the first course shingle, so their tabs don't set directly above the first row tabs.
Racking Shingles
Racking is a shingling method that professional roofers utilize. It's intended to get as many shingles laid as possible without having to move back and forth across the roof
Nail down the first row as far as you can comfortably reach (about 3-6 shingles across). Then do the second row, but leave the end tab unfastened so when you do move, the next first row shingle can slide into position under the loose end.
Work each row up the roof this way, leaving the end tabs unfastened where a lower shingle goes. Rack the rows as far as you can comfortably reach, then move over. Slide the next section of shingles under the unfastened ends, staple/nail both shingles, and continue to rack the rows.
Although racking is a fast way to shingle, it can have drawbacks. If bundles of shingles vary in color, racked areas may look different. It's also easy to forget to fasten shingle ends that get covered up.
Using Roof Jacks
After completing 3 to 5 rows from scaffolding or a ladder, add roof jacks to access the upper rows. Roof jacks are typically thick gauge steel brackets that hold planks in position.
Underneath a completed row of shingles, start a nail through the decking and rafter, hook the jack onto the nail, and hammer the nail down completely. Then fasten a second nail on the lower hook slot. Line up and fasten the opposing jack the same way and set a sturdy plank on the jacks.
NOTE: It's a good idea to put jacks and boards across all the eaves in case you slip or something slides down the roof.
Avoid walking excessively on the felt and shingles during hot days. Both can get soft and are easy to damage and cutting them can get a little gooey. If you can, schedule to avoid the midday hours when the roof is hottest (usually 12:30 to 2:30).更多精彩文章及讨论，请光临枫下论坛 rolia.net
Tear Off
Tearing off an old roof doesn't take a lot of special skill. Basically, you just pry up the shingles using a pitchfork or shovel. Before you begin a tear off, protect trees and shrubs near the house by leaning up plywood sheets.
Locate a construction dumpster, pickup, truck or other container close to the roof. Toss the shingles directly into the container to save from having to pick them up later and to prevent nails from getting lost in the lawn. You may even want to build a temporary chute to funnel shingles into the container. If you're using a pickup or trailer, be careful not to overload it.
Pull up any exposed nails instead of pounding them down. Otherwise, they may work back up. Replace any damaged or missing sheathing, fascia or soffits. We used plywood, but oriented strand board is a good substitute.
It's often difficult to judge how long shingling may take. Of course, the best option is to only tear off as much as can be replaced before bad weather hits. But, you may want to fasten temporary tarps at the roof peaks in case of rain or unpredictable weather.
It's always a good idea to pick up stray nails on the ground at some time during the project. However. since the roof is now exposed, time and weather conditions become important factors. So, it's usually best to do that last or as soon as the roof has underlayment.
Underlayment & Flashing
In most areas of the country, a roof can't withstand exposure to the elements with just a layer of shingles to protect it. An additional underlayment layer(s) is needed to deter water penetration.
Properly sealing out water before shingling requires these elements:
Laying A Waterproofing Membrane
Rolling Out Builder's Felt
Installing Flashing
Fastening Drip Edges
--------------------------------------------------------------------------------
Laying A Waterproofing Membrane
Start by adding a waterproofing membrane along eaves and valleys. These are high-risk areas for leaks; valleys due to improper flashing installation and eaves because of ice dams. We used a thick, bituminous material with an adhesive backing.
The membrane protection provides extra protection against water penetration and is also required by code in "Snow Belt" states at the eaves.
Waterproofing membrane material can be considerably more expensive than just using felt. Most professional roofers recommend the extra protection, and for a do-it-yourselfer, it's good insurance against a leaky roof.
Rolling Out Builder's Felt
Builder's felt (tar paper) is the most widely used roofing underlayment. It comes in rolls and its thickness is gauged in pounds. Typically, a roll of 15 lb. felt may cover about 400 sq. ft. and a roll of 30lb. would cover half that area.
Laying felt is much easier and faster with two people; one rolling, one stapling/nailing. Position the felt roll flush with the gable end.
Working toward the far end or valley, unroll about 5' of felt, square it with the roof edges, press out any wrinkles, and staple/nail it in place as you go. Proceed at 5' intervals to the far end. When you run into a valley, angle cut the felt to lie down the middle of the valley. If you forego the membrane, lay down extra felt at the valleys.
Overlap the second row of felt on the first row by 2". Work up the roof this way to the ridge (peak). Leave the ridge exposed and continue underlayment on the other side. When you reach the ridge, fold the felt over both sides (overlapping 2") and fasten it into position.
Once the roof has underlayment, it can withstand exposure for a few days. However, if it gets wet, the felt may wrinkle up a bit and that increases its chances of tearing by wind.
Installing Flashing
In some cases, metal flashing can be saved and reused during a tear off. But any flashing that is bent, torn or looks bad should be replaced, instead of repaired.
One type of flashing we recommend is galvanized steel, W-shaped valley flashing. It fits in the valley like typical "V" flashing, but has a small ridge sticking up in the middle. This ridge prevents runoff rain from running down one side of the roof and splashing up under shingles on the opposing side.
Set the flashing flush with the drip edges at the bottom of the valley, trimming it with tin snips if necessary. Nail the flashing every 1' or so near its outside edges (never nail in or near the middle). For extra protection, seal seams between pieces and all nailheads with roofing cement.
Fastening Drip Edges
Drip edges are corner-shaped metal strips that nail along the edges of the roof. They allow water from the roof to run cleanly off the edge. Without a drip edge, water may run down the side of the fascia and siding -- causing stains and eventual damage. The drip edge also supports the part of the shingle that extends past the decking.
Along the eave, nail the drip edge under the builder's felt and over the fascia. As an extra precaution, you may want to cover the nailheads with roofing cement then stick the felt down.
At the rake (overhang), install the drip edge over the felt and fascia. This protects the felt from high winds and blowing rain.
NOTE: The length of eaves and rakes may require using more than one piece of drip edge. Like flashing, lap upper pieces over lower pieces.
Shingling
Shingling is a notoriously hot and exhausting job, and working alone is a chore for anyone. It's usually easier, faster and safer to work with a partner. Also, renting a compressor and pneumatic nailer/stapler is money well spent on a big project.
WARNING: Working on a roof is always dangerous. If you feel uncomfortable or unsure about working on the roof, don't. Hire someone to do the work for you.
How Many Shingles?
Getting Straight Lines
Laying The First Courses
Racking Shingles
Using Roof Jacks
Safety Issues and Tips
--------------------------------------------------------------------------------
How Many Shingles?
The surface area of a roof is measured in "squares" of shingles. Each square covers 100 square feet. However, when you buy shingles, they're usually priced per bundle.
Calculate the number of bundles needed by measuring the roof's square footage (length X width). Divide that number by 100 to get the number of squares needed. Multiply the number of squares by 3 (in most cases) or the number of bundles it takes to equal one square. Again, in most cases 3 bundles = 1 square.
Getting Straight Lines
Throughout the shingling process, a sure-fire way to get straight lines and make a roofing job look professional is to snap chalklines.
An experienced roofer may be able to just butt the next shingle square with the previous one, but getting them all straight takes some practice and never guarantees straight lines. So we encourage you to take a few extra minutes and snap some chalklines for key areas.
A horizontal line across the starter strip to guide the top of the first row.
After the first course of shingles is laid, snap a vertical line the height of the roof to indicate the inside edge of the first shingle. This mark will be a guideline for the first shingle in the 3rd, 5th, 7th, etc. rows.
After the second course is laid, snap a vertical chalkline to indicate the inside edge of the second row's first shingle. This mark is the guideline for the 2nd, 4th, 6th, etc. rows.
Laying The First Courses
Lay a starter strip before the first full course of shingles. The starter strip consists of "tabless" shingles that you can make by cutting the tabs from regular shingles. To discourage water penetration, stagger the starter joints from the first course joints.
Shingling methods tends to vary. One person may start with a full shingle on the first row and cut a shingle to fit at the end -- depending on the roof distance. Sometimes, this method creates a tiny 1" to 3" piece at the end. So it's best to measure the length of a full shingle (usually 36") and divide it into the length of the roof (in inches) to figure how the shingles will lay out.
If you want the shingle to overhang (ours extended 1/4"), that factors into the length. That required us to precut the end shingles before nailing them.
In other cases, you may be able to let the first shingle run wild, cut it flush and use that "scrap" piece on the opposing end to complete the row. Again, how you start each row depends on the shingle and roof lengths.
Nail the first course of shingles at each end and middle tabs about 1/2" to 5/8" above the tabs.
Stagger the first shingle of the second course 6" short of the first course shingle, so their tabs don't set directly above the first row tabs.
Racking Shingles
Racking is a shingling method that professional roofers utilize. It's intended to get as many shingles laid as possible without having to move back and forth across the roof
Nail down the first row as far as you can comfortably reach (about 3-6 shingles across). Then do the second row, but leave the end tab unfastened so when you do move, the next first row shingle can slide into position under the loose end.
Work each row up the roof this way, leaving the end tabs unfastened where a lower shingle goes. Rack the rows as far as you can comfortably reach, then move over. Slide the next section of shingles under the unfastened ends, staple/nail both shingles, and continue to rack the rows.
Although racking is a fast way to shingle, it can have drawbacks. If bundles of shingles vary in color, racked areas may look different. It's also easy to forget to fasten shingle ends that get covered up.
Using Roof Jacks
After completing 3 to 5 rows from scaffolding or a ladder, add roof jacks to access the upper rows. Roof jacks are typically thick gauge steel brackets that hold planks in position.
Underneath a completed row of shingles, start a nail through the decking and rafter, hook the jack onto the nail, and hammer the nail down completely. Then fasten a second nail on the lower hook slot. Line up and fasten the opposing jack the same way and set a sturdy plank on the jacks.
NOTE: It's a good idea to put jacks and boards across all the eaves in case you slip or something slides down the roof.
Avoid walking excessively on the felt and shingles during hot days. Both can get soft and are easy to damage and cutting them can get a little gooey. If you can, schedule to avoid the midday hours when the roof is hottest (usually 12:30 to 2:30).更多精彩文章及讨论，请光临枫下论坛 rolia.net