1. flashings and penetrations (all figures are NACHI standards)
1.1. flashings
1.1.1. kickout(moves water away from eve to wall)
1.1.1.1. must be intact and unmodified. check for sealant damage and debris buildup
1.1.2. headwall and sidewall(roof to wall)
1.1.2.1. nominal gap of 1.5 inches and clear of debris
1.1.3. counter and reglet
1.1.3.1. runs 1 inch into mortor between brick
1.1.3.2. usually gumlip because it's faster
1.1.4. valley
1.1.4.1. open
1.1.4.1.1. check for proper taper
1.1.4.2. closed
1.1.4.2.1. check roofing material at transition for decay or damage
1.1.5. roof transition
1.1.5.1. inspect fasteners, check for signs of corrosion as these areas can trap debris
1.2. chimney
1.2.1. 2-10 rule; the chimney should terminate a minimum of 2 feet above any part of the roof within 10 feet. It should also be a minimum of 3 feet tall on its shortest side.
1.2.1.1. If the chimney is wider than 30 inches in the direction perpendicular to the roof slope, it should have a cricket installed on the uphill side.
1.2.1.1.1. check spark arrester or flue cap to ensure is has 4 times the net free opening of the flue opening. should be removable to allow for the flue to be cleaned.
1.3. ventilators
1.3.1. plumbing or stack vents
1.3.1.1. should not be located within 3 feet of an operable window.
1.3.2. air exaust
1.3.2.1. flashings are free of corrosion. condition of storm collar and sealant
1.3.3. combustion
1.3.3.1. cap is intact and in good condition. combustion vents over 5 feet tall should be braced.
1.3.4. attic
1.3.4.1. be sure to check attic space for signs of mositure caused by leaking flashing or disconnected pipes (ie.icing and mold) as mold can occur at 20% with spours forming at 27%
2. attic
2.1. inspection
2.1.1. wear respirator
2.1.2. look for daylight
2.1.3. check around penetrations
2.1.4. check moisture levels of materials. fungal decay can occur as low as 20% moisture
2.1.5. determine if discoloured materials are from current or fixed leaks
2.1.6. identify poor connections and additional problems such as
2.1.6.1. broken, damaged or sagging framing components
2.1.6.2. soffit vents blocked by insulation
2.1.6.3. inadequate structural connections
2.1.6.4. ensure underlayment is cut too if sheathing is cut for ventilation purposes
2.2. ventilation
2.2.1. purposes
2.2.1.1. cools the roof, lengthening lifespan of roof materials
2.2.1.2. prevents heat from entering the home via the roof, lowering cooling costs
2.2.1.3. removes excess moisture vapour
2.2.2. types
2.2.2.1. passive: Passive vents require no electricity, but their effectiveness often depends on their being properly designed for a specific home site. A well-designed passive ventilation system has an intake device located low in the roof, with an exhaust installed near the ridge. with the exception of Gable vents.
2.2.2.1.1. Soffits, you may see individual vents each serving a rafter bay, or continuous vents.
2.2.2.1.2. Gable vents are installed in the gabled ends at opposite ends of the attic. They’re most effective when the vents align with the prevailing winds. This allows high air pressure on the upwind side of the home to push air in and out of the attic effectively.
2.2.2.1.3. Roof vents work in conjuction with soffits. Cold outside air enters through the soffits absorbs heat and exits out the roof vents. Includes ridge vents, "turtle" vents, and occasionally turbine vents.
2.2.2.2. active (requires power)
2.2.2.2.1. Thermostatically controled attic fan, typically found at a gabled end.
2.2.2.2.2. Whole house fan,usually 24 to 30 inches in size. Installed in top floor ceiling central to the house. The fan may be controlled by a thermostat, a timer, or a manual switch. Whole-house fans pull hot air from the living space and exhaust it to the outside through the attic space. They’re typically used with a downstairs window open or with a window-mounted cooling appliance, such as an evaporative cooler, to create a flow of cool air through the home.
2.2.3. other
2.2.3.1. ensure OSB reaches the normal moisture level for the area before roofing in. It is too dry for humid areas when fresh out the factory.
2.2.3.2. Radiant barriesrs are heat reflective material that looks kinda like cardboard covered in tinfoil. It should not be installed right under the roof as this traps heat in the roof. a better option is installation on he attic floor.
2.2.3.3. a minimum of 12 square inches of net free area for every 150 square feet of attic space is required. The amount of ventilation needed is halved if a low perm vapour barrior is installed on the warm side of the attic floor.
3. Structural and Architectural Metal Roofing (sources CRRM and internachi)
3.1. types of roofing
3.1.1. steel
3.1.1.1. coated
3.1.1.1.1. used in all climates
3.1.1.2. uncoated
3.1.1.2.1. rusts naturally in dry climate
3.1.2. copper/aluminium
3.1.2.1. forms protective layer around metal to stop intursion of moisture
3.2. types of damage
3.2.1. excessive oil canning
3.2.1.1. sign of structural movement or failure
3.2.1.1.1. some oil canning willl always be present and is usually not worth reporting as it is cosmetic in nature
3.2.2. corrosion
3.2.2.1. Galvanic Corrosion
3.2.2.1.1. electrolytic damage (ie. rust) or salt damage along the coast
3.2.2.2. Crevice Corrosion
3.2.2.2.1. sign of moisture penetrating system where static water is present
3.2.2.3. Filiform Corrosion
3.2.2.3.1. moisture penetration paint or coating more common in humid environments
3.2.3. bare patches in frost
3.2.3.1. sign of heat loss and abnormal air movement in the system
3.2.4. penetrations
3.2.4.1. check for failure or abnormal wear
3.2.5. weather damage
3.2.5.1. snow load
3.2.5.2. ice damage
3.2.5.3. damage from sorrounding foliage
4. clay and concrete tile
4.1. tile profiles
4.1.1. Low profile tiles (type 3) are flat or close too
4.1.2. medium profile tiles (type 2)may be shallow clay-pan tiles or S-shaped tiles.
4.1.3. High-profile (type 1) tiles are typically barrel tiles.
4.2. other
4.2.1. medium and high profile tile roofs should have birdstop installed beneath the starter course.
4.2.2. damage from footfall is not uncommon around easiest routes of travel and things that require maintenance
4.2.3. at hips, ridges and headwalls Weather-blocking should be installed. It may consist of metal, mortar, pre-formed plastic, -sensitive adhesive rolls, or other material
4.2.4. tiles may be installed on roofs with slopes of 2:12 and greater, although roofs with slopes of 4:12 and less must have a double layer of underlayment.
4.2.5. tiles may vary from 900 to 2,000 pounds per square, checking for compression cracking may be warranted if you suspect a re-roof used a heavier material than the original tiles
4.2.6. A roof tile’s resistance to freeze damage is classified as one of three grades:
4.2.6.1. Grade 1 provides resistance to severe frost action;
4.2.6.2. Grade 2 provides resistance to moderate frost action
4.2.6.3. Grade 3 provides negligible resistance to any frost action.
4.2.7. underlayment, Modern building codes call for underlayment beneath concrete and clay tile to be 30-pound felt or mineral-surfaced roll roofing.
4.2.7.1. low slope requires 19 inches of felt overlap. Standard requires minimum 2"
4.2.7.2. gasketed nails are to be used as fastener for underlayment
4.3. tile side profiles
4.3.1. Interlocking tiles are manufactured with edge profiles that fit together to keep tiles aligned and to help seal against moisture intrusion. They're usually low- or medium-profile.
4.3.2. Overlapping tiles. these are kind of u shape and alternate facing up and down.
4.3.3. Butting, some flat tiles butt up to eachother
4.4. strengths
4.4.1. fire rating of A
4.4.2. Class 3 or 4 hail resistance
4.4.3. Wind resistant, can resist winds of 125 mph
4.5. tools
4.5.1. slate ripper
4.5.2. tile pincers
4.5.3. tile pick/ slaters hammer
4.5.4. bench iron
4.5.5. slate cutter
4.6. Flashing
4.6.1. Building codes call for flashing to be a minimum of 0.019 inch thick
4.6.2. side wall flashing often includes a runoff channel
4.6.3. Valley flashings must extend a minimum of 11 inches on both sides of the valley centerline; and have a formed splash diverter rib at least 1 inch high down the valley centerline.
4.6.3.1. Fasteners here should be stainless steel, copper, aluminum or hot-dipped galvanized steel, but not electroplated.
4.6.4. Vent flashing fastener holes should be caulked
4.7. Fasteners
4.7.1. Tile roofs making use of lugs and battens that are less than 5 in 12 slope and weigh over 9 pounds may not require fasteners.
4.7.2. Nails must be corrosion-resistant, with heads that are a minimum of 5/16-inch in diameter. and long enought to penetrate decking fully or 3/4 inch
4.7.3. When special perimeter fastening is required, the perimeter area includes a minimum of three courses, but not less than 36 inches from roof edges, and from either side of the hips and rakes.
4.7.4. In areas subject to snow, tiles shall be fastened with a minimum of two fasteners. Otherwise typically one is required.
5. Moistness
5.1. Forms
5.1.1. Solid: water expands 10% when it turns to ice, this can destroy inflexible materials.
5.1.1.1. As snow, it adds weight to roofs and holds moisture against the roof.
5.1.1.2. As ice, moisture can form dams that cause melt-water to back up beneath roofing materials and cause leaks.
5.1.2. Liquid: rain can bounce and move unexpectedly, potentially entering the system.
5.2. Problems
5.2.1. material damage
5.2.1.1. Causes Decay in wood and other cellulose based products
5.2.1.2. Weakens granular materials such as drywall. Can completely destroy the material's strength
5.2.1.3. Causes corrosion in metal, potentially damaging fasteners and connectors that often hold roofs together.
5.2.2. Health concerns
5.2.2.1. Mold can appear around 20% moisture and is potentially very harmful to human lung health through fungal infection
5.2.3. Lowers comfort levels by making it feel hotter.
5.3. moist movement
5.3.1. gravity
5.3.2. thermal gradient: moisture moves from warm areas to cold areas
5.3.3. Pressure greadient: moisture, typically vapour moves from areas of high air pressure to areas of low air pressure.
6. wood shake an shingles
6.1. roof maintence
6.1.1. Wood roofs should be maintained on a regular basis. Damaged or missing shakes or shingles should be replaced, and loose ones should be re-fastened.
6.1.2. In areas subject to ice dam formation, nylon stockings filled with snow-melt chemicals can be used to melt through the dam to allow roof drainage.
6.1.3. Squirrels and raccoons may chew or tear wood roofing, especially at areas that are decayed. Shingles with this kind of damage should be replaced.
6.2. life expectancy
6.2.1. varies depends on a number of things that include. climate zone and local environmental factors , such as salt air, heat, humidity, precipitation, and hail; the quality of the shake or shingle; the quality of the installation; the quality of the maintenance; the amount of foot traffic; and any overhanging tree branches.
6.2.1.1. wood roof repair methods
6.2.1.1.1. Repairing damaged areas of wood roofs generally means replacing shakes or shingles. Removing and replacing a shake or shingle is easy and takes less than five minutes. Using a hammer, the shake is driven up far enough to pull the fasteners loose. The shake is then removed.
6.2.2. here are a few places were pressuer treatered shakes and shingles should be use! Angelina, Austin, Brazos, Chambers,
6.3. end of a useful life
6.3.1. Wood roofs may last anywhere from 20 to 60 years. There are many loose, split or missing shakes or shingles. Splits leave inadequate sidelaps. The underlayment or roof deck is exposed. There are many areas where shakes or shingles are thin or eroded Widespread distortion (cupping or curling) is seen across a significant portion of the roof.
6.4. Grading
6.4.1. For shake and shingle grading rules, the IRC generally defers to the CSSB WIND.Shakes and shingles may be UL-certified to resist winds of up to 245 mph and 173 mph, respectively IMPACT Shakes and shingles are available in Class 3 and 4 impact ratings, with Class 4 being the most resistant to impact damage.
6.5. WOOD ROOF INSTALLATION
6.5.1. Roof Sheathing Requirements Both shakes and shingles may be installed on either solid or spaced roof sheathing. You’ll be inspecting the sheathing from the attic. Watch for other problems while you’re there. Note that the center support post in the roof framing pictured below has been cut. Spaced Sheathing Both shakes and shingles can be applied over spaced sheathing, with 1x4 as the minimum size. In new construction where 1x4s are used on 10-inch centers, an additional 1x4 should be installed between sheathing boards. In older homes, you’ll see a variety of board sizes and you should refrain from reporting this as a defect unless you see failure of some kind. SHAKES When shakes are installed on spaced sheathing, the distance from centerline to centerline of the sheathing boards should match the weather exposure of the shakes. So, for example, 24-inch shakes with a 10-inch exposure should have boards spaced so that they measure 10 inches from center to center, and 18-inch shakes should have sheathing spaced a maximum of 71⁄2 inches from center to center. Roofs covered with shakes are usually sheathed with 1x6 boards. For new construction in most places in the U.S., the maximum gap allowed between boards is 31⁄2 inches. Again, in older homes, limit your comments to signs of failure, such as sagging rafters or sheathing. The advantage of spaced sheathing is that it allows shakes and shingles to dry more easily. SHINGLES Spaced sheathing for wood shingles should also be installed so that the board spacing matches the shingle exposure. For example, if the exposure is 51⁄2 inches, the sheathing boards should be installed on 51⁄2-inch centers. SOLID SEATHING The CSSB recommends solid sheathing for shakes in new construction. However, installing shakes on spaced sheathing was widely accepted in the past. Solid sheathing can be used under shakes and shingles, and may be required in areas subject to seismic activity and when treated shakes and shingles are used.
6.6. UNDERLAYMENT AND INTERLAYMENT
6.6.1. In cold climate zones where ice dams are common, both shake and shingle roofs should have an ice barrier installed as eave protection along the lower roof edge. Even if shakes or shingles are installed on spaced sheathing, the roof deck beneath the ice barrier should be solid sheathing. Shakes and shingles have very different requirements regarding the installation of a water-resistant membrane in the field. SHINGLES Both the CSSB and the IRC recommend that shingles in the main portion of the roof have no underlayment installed due to concerns about moisture, especially condensation. The exception is where an ice barrier is required at the eave. Interlayment for Shakes Shakes should never have underlayment installed except where an ice barrier is required over solid sheathing. Instead, interlayment is required. Interlayment consists of an 18-inch-wide strip of 30-pound black felt installed between courses of shakes. The bottom of the felt should be positioned above the butt of the shakes at a distance equal to twice the exposure. The interlayment should never be visible. Interlayment acts as a weather baffle and helps prevent wind-driven snow and rain from penetrating the roof. Because shakes are usually rougher and coarser than shingles, wind-driven precipitation is more likely to penetrate shakes than shingles. Interlayment requirements may vary by area. Allowable Exposure The proper exposure for both shakes and shingles is determined by the length and the grade. The exposure of a shake or shingle is that portion which is exposed to weather. So, if you look at a roof with 24- inch shakes installed and you can see 10 inches of the length of each shake, the exposure is 10 inches. Both shakes and shingles have minimum slope requirements. According to the IRC, shakes should never be installed on roofs with slopes of less than 4:12. Shingles should never be installed on roofs with slopes of less than 3:12. But on roofs with slopes of between 3:12 and 4:12, exposures should be reduced according to shingle length and grade. Although decreasing shake or shingle exposure is acceptable, the maximum exposure should never be exceeded. Excessive exposure lowers the roof’s resistance to wind damage and distortion from weathering. Spacing Between Shakes and Shingles Wood shakes and shingles swell when they get wet and shrink when they dry. Because of the structure and orientation of wood cells, there will be more dramatic movement across the width than in the length. For this reason, it’s important to leave adequate space between shakes or shingles in the same course. Limitations on spacing may vary according to the AHJ in the area where the inspection is being performed. It’s usually the CSSB or the IRC. Spacing between taper-sawn shakes that are pressure-treated with a preservative is 1⁄4-inch to 3⁄8-inch.
6.7. FASTENERS
6.7.1. Both shakes and shingles should be installed with corrosion- resistant fasteners, such as aluminum, stainless steel or hot-dipped zinc-coated nails. Electro-galvanized, zinc-coated staples are available, but staples are not available hot-dipped.
6.7.2. The CSSB does not recommend the use of electro-galvanized fasteners. In coastal environments, electro-galvanized fasteners are a defective installation due to their excessively short service life.
6.7.3. Some types of fasteners may not be of a material that is compatible for use with shakes or shingles that have been chemically pressure- treated.
7. HAIL DAMAGE (sources include internachi, Institute for Catastrophic Loss Reduction, )
7.1. cause
7.1.1. formed inside storms when updrafts carry dirt and dust particles into cooler air, icing after coming in contact with moisture creating hailstones, similar to how pearls are formed
7.2. where
7.2.1. can happen anywhere but most severe storms are confined to southern alberta
7.3. damage
7.3.1. AIR Worldwide suggests that a low probability/worst case storm event could result in insurance damage claims of up to $13.5 billion from a single event.
7.3.1.1. types
7.3.1.1.1. minor localized granule loss
7.3.1.1.2. dents in metal vents, gutters and downspouts
7.3.1.1.3. damage should be random across the roof
7.3.1.1.4. Elevation Damage
7.3.1.1.5. sizes
7.3.1.2. damage specs
7.3.1.2.1. Material Hail Size Damage Size 3-tab organic shingles 1 inch 3-tab fiberglass shingles 11⁄4 inches cedar shingles 11⁄4 inches fiber-cement tiles 11⁄4 inches flat concrete tiles 11⁄4 inches heavy cedar shakes 11⁄2 inches 30-year laminated shingles 11⁄2 inches 1 built-up gravel roofing 2 S-shaped concrete tiles 2
7.3.1.3. Intentional Damage
7.3.1.3.1. damage that is concentrated in areas away from the roof edge,
7.3.1.3.2. damage in which appears as a series of short arcs,
7.3.1.3.3. damage which appears as separate groups,
7.3.1.3.4. hail does not leave scratches in the material it hits
7.3.2. test square
7.3.2.1. 10ft by 10ft
7.3.2.1.1. area size should always be 100 square feet, no matter what the shape
8. Slate
8.1. installation
8.1.1. weight
8.1.1.1. 3500 lbs epr square is considered heavy, though slates can weigh up to 8000 lbs per square
8.1.1.2. framing , rafter and sheathing must be always checked for sagging from underneath/in the attic
8.1.2. Slope
8.1.2.1. slates installed on slopes under 4/12 should always have waterproof underlayment
8.1.2.2. modern building code forbids installing slates on less than 4/12 slope, though older buildings may still have them
8.1.3. sheathing
8.1.3.1. can be spaced boards, battens or panels, such as OSB or plywood
8.1.3.2. 3/4 inch minimum, slates may break on 1/2 inch
8.1.3.3. modern codes call for solid sheathing beneath slates
8.1.4. underlayment
8.1.4.1. felt is inappropriate as slates will outlast it significantly
8.1.4.2. inspect underlayment from the attic if possible, as it will be hard to inspect without disturbing the slates
8.1.4.3. many slate roofs are installed with no underlayment, so long as the slates are installed correctly it's no issue
8.1.5. courses
8.1.5.1. first course should be doubled (as with other roofing systems)
8.1.5.1.1. chamfer down on first run, resting on a cant strip, chamfer up on remaining runs. slates may crack if not cant stripped
8.1.5.1.2. slates overhang 1.5-2 inches, adequate to protect framing
8.1.5.2. minimum sidelap seperation for vertical joints in adjacent courses is 3 inches
8.1.5.3. standard minimum headlap is 3 inches, accounting for the headlap half the remaining slate should be exposure. headlap increases to 4 in under 8/12
8.1.6. fasteners
8.1.6.1. nailing is typical but hooks may be used, esp for repairs
8.1.6.2. nails should be properly countersunk
8.1.6.3. nails should not be slammed overly tight to prevent cracking the slate from expansion pressure
8.1.6.4. underdriven nails can damage the next course of slates
8.1.6.5. nails should always be copper, stainless, or hot dip galv. stainless are ideal. electroplate galv are unacceptable
8.1.6.6. if the fasteners are failing, it may be possible to remove and reinstall the slates without damaging them. if the slates are near the end of their lives this would not be wise.
8.1.6.7. if a slate roof is leaking and there is no damage slates, check nail holes and nailing methods
8.1.6.8. slates can and will outlast fasteners/underlayment
8.1.7. Valleys
8.1.7.1. open valleys are preferable to closed valleys
8.1.7.2. valleys should have taper to be wider at the bottom, but it is not a strict requirement
8.1.7.3. do not nail through valley metal. heavy slates may require an extra nailhole punched
8.1.7.4. older roofs may have rounded valleys. if a rounded valley is encountered, simple leak checks are done and it isn't required to confirm proper installation.
8.1.8. Hips
8.1.8.1. should have waterproof base underlay
8.1.8.2. capped hips, may have step flashings between courses, but sometimes the base membrane is used as step flashing - both are acceptable
8.1.8.3. hip caps are not mitered at the joint, and may be either caulked of left as is - either may be acceptable
8.1.9. Ridge
8.1.9.1. AKA finish course, two horizontal nails should be installed on each side of the finish course, upper nail is backing for ridge cap slates and lower nail for the last course of field slates
8.1.9.2. saddle-ridge method uses cap slates that overlap each other and look similar to asphalt shingle ridge caps. This is the most common ridge detail
8.1.9.3. strip-ridge method looks as though field slates continue on to meet at the ridge, and resembles a mitered hip
8.1.10. flashing
8.1.10.1. typically the first thing to fail on a slate roof and should be the first thing to inspect, especially at or near 70 years old
8.1.10.2. take note of temporary repairs such as caulking or mastic, and the general condition of the flashings
8.1.10.3. it is likely more cost effective to replace the entire roof if over 25% of the slates would be disturbed by repairing or replacing flashings
8.1.10.4. flashings typically should be 4 inches up and 4 inches under (the slates), but older homes may not meet this requirment and still be acceptable
8.1.10.5. copper flashings are typical on slate roofs. copper flashings should not be secured with galv nails as the nails will degrade and fail faster than expected.
8.2. Manufacturing
8.2.1. fading/unfading slate
8.2.1.1. incorrect product can be installed if not careful
8.2.1.2. colour can determine origin quarry, quality of slate, but a specialist should be consulted to determine specifics
8.2.1.3. fading slates can diverge up to 90% from their original appearance (intentional)
8.2.2. slate density/durability
8.2.2.1. slates exposed to high pressure are more durable/more dense
8.2.2.2. slates exposed to high temperatures can be more dense
8.2.2.3. moisture absorbtion can reduce slate desnity/durability
8.2.3. slate grades
8.2.3.1. S1 grade slate rated for 75+ years
8.2.3.2. s2 grade slate rated for 40-75 years
8.2.3.3. s3 grade slate rated for 20-40 years
8.2.3.4. slate graded by astm lab
8.2.3.4.1. testing is rarely done on residential slate roof
8.2.4. slate quality
8.2.4.1. slate quality can vary greatly even in the same quarry depending on the dig
8.2.4.1.1. high carbon, IE dark colour or dark ribbon slates, are less durable
8.2.4.2. imported slates may vary greatly in quality
8.2.4.2.1. chinese slates low quality, high carbon content, brittle, especially notable in cold climate
8.2.4.2.2. spanish slates also very low quality
8.2.4.2.3. india and brazil low quality slates
8.2.4.2.4. man all the fuckin imported slates are shit
8.2.4.2.5. look carefully for mineral occlusions, color fading, delamination, and broken slates. Disclaim the slate roof in your report, stating that some types of ribbon slates and imported slates have a reputation for low durability.
8.2.5. Weathering
8.2.5.1. delamination or seperation of cleavage planes (layers)
8.2.5.1.1. minerals in slates expand over the long term due to moisture, causing delamination
8.2.5.1.2. denser slates are more resistant to delamination and "rot"
8.2.5.2. dissolving minerals from moisture cycles resulting in porous-ness
8.2.5.2.1. as slates delaminate, they open holes for moisture to penetrate deeper layers and "rot" or soften the slate
8.2.5.2.2. UV radiation can combine with moisture to break down slates faster, leaving white powder on the surface called efflorescence
8.2.5.3. occlusions (multiple) or deterioration (single) can occur from mineral impurities
8.2.5.4. slates with moisture trapped inside can rot the wood underneath, hard to notice, though the slate itself may last a long time in that condition
8.2.5.5. slates are generally more resistant to factors that affect other roofing types (thermal expansion, the freeze-thaw cycle, and UV deterioration)
8.2.5.6. moss may be a sign of moisture damage, and the slates may be damaged underneath
8.3. other
8.3.1. interlayment, increasing the exposure of the slates significantly and laying felt between, increases chances of leaking significantly after the felt breaks down
8.3.2. inspection specific
8.3.2.1. accessing the completed roof should be done by a hook ladder to avoid damaging the slates or injuring yourself. DO NOT WALK ON SLATE ROOFS
8.3.2.2. be sure to include the limitations of the inspection in your report and advise that a certified contractor may be required to perform a further inspection if you feel it necesary
8.3.2.3. inspections are typically done using binoculars. scan the roofs edge, ridges, hips, sidewalls, headwalls and penetrations. scan field slates for damage or degredation. scan for poor work and installations.
8.3.2.4. design problems that affect other types of roofs can also affect slate roof, such as poor attic ventillation. steeper pitched roofs extend the lifespan of slates.
8.3.2.5. inadequate headlap is the most common point of failure on slates themselves
8.3.3. broken slates
8.3.3.1. chips are normal, but a slate corner is considered broken if it exceeds a triable 1x1 inches from the corner of the slate
8.3.3.2. if there is a lot of broken slates on the eave, check for cant strip
8.3.3.3. poorly supported slates can be broken by snow and ice sliding off the roof
8.3.3.4. anyone walking on the roof will most likely damage the slates
8.3.3.5. falling branches, rocks, or balls are a common cause cause of broken slates
8.3.3.6. ladders can damage slates
8.3.4. snow guards
8.3.4.1. snow guards that are hooked to the slates instead of nailed to the framing can rip the slates down
8.3.4.2. poorly installed snow guards are a defect, falling snow can cause serious injury
8.3.4.3. snow guards should be properly secured or they may lift the slate above them
8.3.4.4. guards may be installed too far apart to save money, and can lead to overburdening the snowguard that will damage the slates as above
8.3.4.5. it is not typically in the scope of your inspection to ensure the right type of snow guard is used, or if they are spaced correctly, beyond identifying obvious failures
8.3.5. gutters
8.3.5.1. gutters may be built into the roof and subject to abuse, and should be inspected as possible
8.3.5.2. older homes with hidden gutters may have downspouts that tie into the home plumbing, and could be the cause of leaks on an otherwise copasetic roof
8.3.6. pests
8.3.6.1. pests are a common problem in every type of roof, and a common cause of leaks in every type of roof, and you should investigate if you think they are present
8.3.7. slates may make a rattling noise in wind known as chattering, especially on steep roofs, that can be alarming to homeowners. this is common and not a cause for concern by itself, and it's worth noting in the report if you think it's occuring
8.3.8. composites
8.3.8.1. composite slates can be cast from a stone slate mold, and are generally identified by having a flat face and beveled edges
8.3.8.2. unless you are able to access the manufacturer specs for that specific type of composite slate, it will be difficult to inspect their condition properly
8.3.8.3. if specs cannot be acquired, inspection should focus on flashings, fasteners, and for obvious failure points. be sure to document.
8.4. Repairs
8.4.1. hook
8.4.1.1. the broken slate should be extracted and fasteners removed with slate puller
8.4.1.2. the hook should be nailed into the sheathing between the existing slates
8.4.1.3. the hook should be hung to support the slate at the proper exposure and to match the existing course, unless the butts are intentionally staggered
8.4.2. copper strip
8.4.2.1. extract the broken slate and fasteners with slate puller
8.4.2.2. the replacing slate has a new hole punched to align with the existing slates
8.4.2.3. a copper strip is bent and placed to cover the nail. the existing slates will weigh down the copper strip
8.4.3. copper tab
8.4.3.1. extract the broken slate and fasteners with slate puller
8.4.3.2. the copper tab is nailed into place to align with the replacing slate
8.4.3.3. the replacement slate is slid into place and the tab is bent upwards to support the new slate
8.4.3.4. the copper must be heavy enough gauge to take the weight of the slate
8.4.4. Improper
8.4.4.1. slate should not be repaired with sealant
8.4.4.2. slates should not be fastened with construction adhesives. this is common for repairs from novices
8.4.4.3. exposed fasteners are unnacceptable
8.4.4.4. broken slates are not acceptable for repairs, even if the damage is minor
8.4.4.5. non matching slates are improper for repair as they may fade to different colours over time