Commerical Industrial Roofing Systems\Reroofing (Johns Manville)

	Reroofing

11.4 Interview with Building Occupant

11.4.1 Before actually inspecting the building, the building occupant should be interviewed. This may provide valuable information regarding the condition of the existing system, as well as the source of some of the problems. The following list of questions for the building occupant may be valuable in evaluating the existing system:

1.	Is the roof now leaking? For how long?
2.	Where is the water entering the building?
3.	Does water enter the building with every rain, or only during a driving rain?
4.	Does water enter the building as soon as it starts raining, or does it take some time for the water to appear?
5.	Does the water stop entering the building as soon as it stops raining, or does the roof continue to leak for hours/days?
6.	Does water enter the building during clear dry weather or only during very cold weather (condensation)?
7.	Do you know the cause of the roof leaks?
8.	Has anyone attempted to repair the roof, and if so, do you know what has been done? Were the past repairs successful?

11.5 Interior Inspection

11.5.1 Following the interview with the building occupant, an inspection should be made of the underside of the structural roof deck. If possible, the following items should be checked on all decks, regardless of type:

1.	Rust/water stains
2.	Asphalt drippage
3.	Indications of structure failure, corrosion or weakness
4.	Deck span
5.	Presence, type, and condition of mechanical fasteners protruding through the deck

11.5.2 For specific deck types, also note the following:

Steel Decks

1.	Unusual deflection of the deck
2.	Existence of side lap fastening
3.	Condition of spot welds

Pre-Cast Units

1.	Configuration of unit ("Ts", "TTs", slab, waffle slab, hollow core)
2.	Size of joint between panels
3.	Cracks or spalling in panels
4.	Damage to edge of panels
5.	Presence and condition of weld plates
6.	Camber
7.	General conditions and evenness

Lightweight Insulating Concrete

1.	Substrate (corrugated metal, slotted metal, form board, wood, structural concrete)
2.	Existence and condition of underside venting feature

Structural Concrete

1.	Cracks
2.	Spalling or efflorescence

Cementitious Wood Fiber Planks

1.	Sagging of panels
2.	Condition of tongue and groove joint
3.	Presence and condition of side lap clips
4.	Indications of panel movement
5.	Indications of rot (punkiness) or loss of integrity

Gypsum Plank

1.	Condition and dimension of joint
2.	Sagging of panels
3.	Spalling or punkiness
4.	Indication of panel movement

Poured Gypsum

1. Substrate and condition (form board, metal, concrete)

Wood Board and Plywood

1.	Condition and dimension of joints
2.	Presence of blocking or ply clips at plywood joints
3.	Indication of dry rot or insect infestation
4.	Excessive knot holes
5.	Warping
6.	Condition of purlins or joists
7.	Panel deflection

11.5.3 Roof leaks should be observed from the inside of the building to determine whether the water entry is occurring through or near roof drains, air conditioning ducts, or other penetrations. A roof leak in the vicinity of a change in deck types could indicate a roof split, due to the lack of an expansion joint. Leaks at a wall line could indicate the failure of a base flashing, or water entry through the wall, coping or gravel stop.

11.6 Exterior Inspection

11.6.1 Before inspecting the existing roof system, a general inspection of the exterior of the building should be made from ground level. Bowing of masonry walls or tilting of pre-cast panels indicate structural movement. Cracks in the masonry at corners, window openings, doorways, or additions may indicate structural problems which must be resolved prior to roofing.

11.6.2 Efflorescence on masonry walls indicates water entry through the masonry or coping. If replacement/recover is to succeed, the masonry walls must be waterproofed.

11.6.3 Water stains, moss, or algae on masonry usually indicate a deficiency in the gutter, gravel stop, down spouts, scuppers, or through-wall flashing. It is likely that the roof adjacent to these stains will also be wet.

Reroofing - Page 2