Structure Inspection Section#4 Roof Framing Quiz#6

You should have finished Study Session 5 and Quick Quiz 5 before starting this Study Session. This Study Session covers engineered wood roof systems.

The estimated completion time is 30 minutes.

Objectives
At the end of this study session, you should be able to:

• Identify a wood "I" joist.
• Describe the basis of "I" joist construction.
• Describe the common conditions encountered with wood "I" joists.
• Identify typical conditions with "I" joists.
• Describe the function of sheathing.
• Identify types of sheathing.
• Identify common sheathing conditions.

Describe a shearwall, mentioning materials, fastening, and location.

Shearwalls are 3/8 to 1/2-inch plywood or waferboard nailed to exterior (and sometimes interior) stud walls of home to resist the lateral forces of earthquakes and prevent racking. They must extend the full wall height without interruption to be effective. They are nailed every 4 to 6 inches at panel edges and every 12 inches in the field of the panels. All edges must rest on solid wood framing or blocking. Hold-downs should be provided at each corner and each end of the shearwall.

Give three possible causes of sagging sheathing.

1. Overspanning 
2. Excess loads 
3. Deteriorated wood 
4. Panel type sheathing installed in the wrong direction 
5. Inadequate edge support

In both plank and panel roof sheathing, vertical joints should not run continuously up one rafter or one truss. Adjacent vertical joints should be staggered. Explain why.

The roof is stronger if vertical joints are staggered. Vertical joints are weaknesses in the roof panel. Lining up all the weakness will tend to make the roof act as several smaller panels rather than one large one.

List five types of hardware that may be used to improve the ability of a home to resist earthquakes.

1. Sill anchors
2. Hold downs (tie downs)
3. Straps
4. Hangers
5. Post caps
6. Hurricane clips (ties)

Name three key issues in hurricane resistance for houses.

1. The roof sheathing must be well secured to the roof framing. 

2. The roof framing must be well secured to the walls

3. Openings like doors and windows must be protected from flying debris. 

What is FRT plywood and where was it commonly used?

Fire resistant Treated (FRT) plywood is typically used in row or town home close to the party walls to avoid building parapet walls. A chemical treatment in the wood was designed to char the wood at relatively low temperatures, raising the auto-ignition temperature of the wood and helping to control the spread of fire.

What is the difference between a wood I-joist and traditional lumber?

Wood I-joists are engineered and manufactured wood systems that have a top and bottom chord and a web that joins them.

Is it acceptable for wood I-joists to lean against each other at the peak the way rafters can?

No

It is acceptable to notch a bird's mouth into the bottom plate of an I-joist.

No

Structure Inspection Section#4 Roof Framing Quiz#5

You should have finished Study Session 4 and Quick Quiz 4 before starting this Study Session. This Study Session covers roof trusses.

The estimated completion time is one hour.

Objectives
At the end of this study session, you should be able to:

• Identify different types of roof trusses.
• Describe the functions of roof trusses.
• Describe the basics of roof truss construction.
• Identify the typical conditions encountered with roof trusses.
• Identify problems encountered with roof trusses.

Give two possible causes of truss sag.

1. Excess load 
2. Overspanning 
3. Weak connections 
4. Cut or damaged webs or chords

On a house that has a truss roof structure, if you see a gap at the top of a partition wall between the wall and the ceiling, what might you suspect?

Truss uplift.

On a roof truss, what is the difference between a chord and a web?

A chord is part of the perimeter of a truss. Webs are the internal members

There are many different kinds of trusses. List as many as you can.

King post, queen post, fink, howe, fan, belgian or doublefink, scissor, mono, pratt, warren, gable end.

What is a common solution for truss uplift?

Attach moldings to ceilings but not walls, and allowing the ceiling drywall to float are common solutions for truss uplift.

Why is it common to find sagging of roof sheathing on trusses?

Trusses are further apart than most rafters. Trusses are often 24 inches on center and some common plywood and waferboard sheathings are not thick enough to span 24 inches without sagging under live load.

Why might a drywall ceiling sag below trusses?

Drywall may sag because ½ inch drywall cannot stand the 24 inches between trusses without sagging, especially if the drywall has been wet as a result of condensation, or during construction and finishing.

Where are notches and holes commonly permitted in trusses?

Notches and holes are not permitted in webs and chords.

Structure Inspection Section#4 Roof Framing Quiz#4

You should have finished Study Session 3 and Quick Quiz 3 before starting this Study Session.

The estimated completion time is 45 minutes.

Objectives
At the end of this study session, you should be able to:

• Identify collar ties, knee walls and purlins.
• Describe the typical conditions encountered with collar ties, knee walls and purlins.
• Identify typical problems with collar ties, knee walls and purlins.

What can cause sagging of the top plate on a knee wall?

The top plate of a knee wall may sag if it is a single plate and if the studs are not lined up with the rafters above.

What is the difference between a knee wall and a purlin?

Knee walls and purlins both provide mid-point support for rafters. Knee walls provide their support by transferring the loads down to ceilings joists and walls or beams below. Purlins act as beams running along the underside of rafters.

What is the ideal location for a collar tie?

Collar ties should be located halfway up the rafters.

What is the main function of a collar tie?

Collar ties help prevent rafter sag.

What is the minimum roof slope required for collar ties to be effective?

4 in 12

Why is lateral support required on long collar ties and how might this support be provided?

Because collar ties are in compression, they might buckle. Lateral support helps to prevent buckling.

Structure Inspection Section#4 Roof Framing Quiz#3

You should have finished Study Session 2 and Quick Quiz 2 before starting this Study Session. This Study Session covers the common conditions encountered with rafters, roof joists and ceiling joists.

The estimated completion time is one hour.

Objectives
At the end of this study session, you should be able to:

• List eight common problems with rafters, roof joists and ceiling joists.
• List three causes of sagging rafters or ridges.
• List five causes of rafter spread.

Explain why a ridge beam helps prevent rafter spread.

Rafters are less likely to spread when there is a ridge beam because the rafters hang on this structural member. With a simple ridge board, the rafters are not prevented from dropping at the ridge. A ridge beam, if properly installed, helps prevent the rafters from dropping or spreading.

Give five causes of rafter spread.

1. Ceiling joists running parallel to rafters 
2. Ceiling joists not well connected to rafters 
3. Ceiling joist splices not secure 
4. Rafters not well secured to the structure 
5. Ceiling joists removed to create cathedral ceilings.

Give three causes of sagging rafters.

1. Rafters overspanned or undersized 
2. Too many layers of roofing materials 
3. Excessive loads

Give two examples of how you might differentiate between a roof leak and a condensation problem in an attic.

1. Condensation tends to be more uniform and widespread than leakage. Condensation is uniform laterally across the roof. 
2. Leaks tend to run down sloped roof surfaces following gravity.

How might you tell the difference between sheathing sag and rafter sag from the exterior of the house?

Sagging rafters cause a dishing in the entire roof surface and/or a sag at the ridge. Sheathing sag is a repetitive pattern across the roof between rafters, trusses or roof joists.

Where rafters have been cut to accommodate a skylight, for example, the roof loads must be transferred to adjacent rafters. How is this done?

Headers and trimmers (doubling of rafters) strengthen the roof around openings for dormers, skylights, etc. This is similar to the headers and trimmers created in floor systems at stairwell openings.

Proper endbearing is required for rafters and ceiling joists. Generally speaking, the minimum recommended endbearing is __ inches. (Insert a number.)

1-1/2

Structure Inspection Section#4 Roof Framing Quiz#2

You should have finished Study Session 1 and Quick Quiz 1 before starting this Study Session. This section introduces our discussion of rafters and roof and ceiling joists.

The estimated completion time is 45 minutes.

Objectives
At the end of this Study Session, you should be able to:

• List five functions of rafters, roof joists, and ceiling joists.
• Define in one sentence each rafters, roof joists and ceiling joists.
• Describe in one sentence each hip, valley and jack rafters, and ridge boards and ridge beams.

Ceiling joists are often not continuous from one side of the building to the other. In this case, they are spliced over a central bearing wall. Why do they have to be securely tied together?

Ceiling joists help prevent rafters and the tops of walls from being pushed outward by live loads on the roof. Ceiling joists are often in tension, running from the bottom of one rafter to another. They must be continuous to resist these forces.

Define hip rafter, valley rafter, and jack rafter.

A hip rafter is a rafter that forms a roof hip and supports the jack rafters on either side. The hip rafter follows the line of the hip. A valley rafter follows the line of the valley in a roof and supports the jack rafters on either side. Hip and valley rafters are typically one size larger than other rafters in the roof structure. Jack rafters are short rafters that either have their top end at a hip rafter or their bottom end at a valley rafter.

Define rafters, roof joists, and ceiling joists

Rafters are sloped structural members on steep roofs that support sheathing and run from the roof peak down to the eaves. They may be 2 by 4 to 2 by 10?s and are typically spaced 12 ? 24 inches on center. Roof joists are horizontal or nearly horizontal framing members on low-sloped roofs that carry the sheathing, roof covering and live loads above to walls or beams. Roof joists can be thought of as low-sloped rafters. Some roof joists also carry ceiling finishes. Ceiling joists are horizontal members that support insulation and ceilings. They are used with rafters and may support attic floors. Ceiling joists often tie the bottom ends of opposing rafters together to make a structurally sound triangle of the roof assembly.

How is the span of a rafter measured?

The span of a rafter is determined by its horizontal projection.

List five functions of roof framing members.

1. Carry the live loads of wind, rain, snow and people

2. Carry the dead loads of roof sheathing, roof covering and roof-mounted equipment

3. Support the dead loads of insulation and ceiling finishes

4. Laterally support the walls of the building, preventing racking and wall or roof spreading

5. Create an attic space, a ventilation space and support for soffit and fascia

What is a typical, chronic problem with flat and cathedral roofs?

One of the chronic problem with both flat and cathedral roofs is a lack of ventilation. Where insulation is between the roof joists or rafters, there should be a space above to allow moist air and heat to be removed from the roof space. 

What is the difference between a ridge board and a ridge beam?

A ridge board does not carry rafter loads. A ridge beam does. A ridge beam will prevent rafter spreading. A ridge board will not. A ridge board is typically 1 by x material. A ridge beam is typically at least 2 by x material. Ridge beams require vertical supports below. Ridge boards do not.

Structure Inspection Section#4 Roof Framing Quiz#1

This Study Session includes the scope of roof inspection and an introduction to inspecting roof structures.

The estimated completion time is one hour.

Objectives
At the end of this Study Session, you should be able to:

• List three situations where you would not fully inspect attics.
• List seven basic roof shapes.
• Define steep roofing in one sentence.
• Define flat roofing in one sentence.
• List six functions of roofs.

Give at least two examples of how you might damage the property while entering an attic space

1. Collapse duct work 
2. Put your foot through the ceiling 
3. Fall through a ceiling 
4. Disturb an electrical connection

It is a good idea to start the inspection of the roof from a distance (other than the side of the street). What kinds of things are you looking for with respect to the roof structure?

1. A sag in the rafter or ridge system

2. Dishing in the field of the roof

3. Spreading of the roof rafters (often visible at the soffits), or the top of the wall

List at least four things that you are looking for inside the attic with respect to the roof structure.

1. Poor endbearing

2. Weak connections (especially in earthquake or hurricane area)

3. Rot or insect damage

4. Mechanical damage

5. Fire damage

6. Cracks or sagging of the interior finishes

Under what three conditions are you not required to enter the attic space?

1. The access is blocked 
2. You might damage property 
3. It might be dangerous

Why might the loads on the roof structure increase when you add attic insulation?

More snow will accumulate on the roof.

Why might the pull-down attic staircases be dangerous?

The pull-down attic staircases might be loose or unstable.

The Standards require you to describe the roof structure.

True

The Standards require you to enter every attic space.

False

The Standards require you to inspect the roof structure.

True

The Standards require you to report how you inspected the attic.

True

Structure Inspection Section#3 Wall System Quiz#6

You should have finished Study Session 5 and Quick Quiz 5 before starting this Study Session.

The estimated completion time is 45 minutes.

Objectives
At the end of this study session, you should be able to:

• Explain in one sentence the functions of arches and lintels.
• List five materials used in arches and lintels.
• List nine common lintel problems.

Briefly describe the functions of arches and lintels. (Hint: use the words "loads", "transfer", and "openings" in your discussion.)

Arches and lintels transfer dead and live loads above and around openings.

List nine common arch and lintel problems.

1. Missing

2. Cracks

3. Mortar deteriorating or missing

4. Wood supporting masonry

5. Stone or brick deterioration

6. Sagging, leaning or rotating

7. Endbearing

8. Rust

9. Rot/insect damage

What materials are used for arches?

Materials used for arches are often the same materials used for walls and may be stone, brick, or concrete.

End bearing for lintels in masonry should be at least __ inches. (Insert a number.)

6

End bearing for lintels in wood frame walls should be at least __ inches. (Insert a number.)

1-1/2 

Wood lintels on the exterior face of a building are particularly prone to _____ problems.

Rot

Masonry resting on wood is a less than ideal arrangement.

True

The top of the exposed edge of a steel lintel should be caulked.

False

With masonry walls, the lintel size is independent of the number of stories above.

True

With wood frame walls, the lintel size is independent of the number of stories above.

False

Structure Inspection Section#3 Wall System Quiz#5

You should have finished Study Session 4 and Quick Quiz 4 before starting this Study Session. This Study Session covers masonry veneer walls.

The estimated completion time is one hour.

Objectives
At the end of this study session, you should be able to:

• List five ways to identify masonry veneer walls.
• Describe in two sentences the vented rain screen principle.
• List thirteen common problems with masonry veneer walls.

Briefly describe the vented rain screen principle for a brick veneer wall. (Point form is fine. Hint: Use the words "cavity", "pressure", "drainage", "flashing", and "weep holes" in your discussion.)

The vented rain screen principle includes a one-inch cavity between the masonry wall and the wood frame wall. Weep holes in the masonry veneer allow air to pressurize the cavity, reducing the pressure differential across the brick. This helps to reduce the amount of moisture driven through the wall by wind pressure. The weep holes not only allow air into the cavity, but also allow moisture to drain out. A flashing at the bottom of the cavity extends up behind the sheathing paper and out across the top of the foundation below the brick. Water is guided out of the wall through the weep holes.

Give five techniques to help differentiate masonry veneer walls from solid masonry walls.

Characteristics of veneer walls

1. The presence of weep holes

2. The presence of wood studs inside

3. The absence of header bricks

4. The absence of masonry arches

5. A single wythe of brick supported on a metal angle fastened to the exterior of the foundation

List 13 common masonry veneer wall problems. (Think of the masonry veneer part only.)

1. Cracked

2. Bowing or leaning

3. Mortar missing or deteriorating

4. Stone/brick deterioration (including spalling)

5. Weep holes missing or obstructed

6. Flashing missing or ineffective

7. Efflorescence

8. Too close to grade

9. Wavy brick walls

10. Excess corbelling

11. Bricks on their sides

12. Sagging lintels or arches

13. Prior repairs

List seven common veneer wall problems. (Think of the wood frame part only.)

1. Rot and insect damage

2. Leaning or racking

3. Bowing or buckling

4. Excessive holes, notches or mechanical damage

5. Sagging top plate

6. Lack of fire stopping

7. Sagging lintels

What kind of masonry crack patterns do rusting steel lintels over the windows cause?

Horizontal cracks usually radiating out from the corners of the window. Occasionally there are vertical cracks over the corners of the windows.

In masonry veneer walls -

Weep holes are often found

Brick veneer walls are watertight.

False

The masonry veneer is a loadbearing part of the structure.

False

Structure Inspection Section#3 Wall System Quiz#4

You should have finished Study Session 3 and Quick Quiz 3 before starting this Study Session.

The estimated completion time is one hour.

Objectives
At the end of this study session, you should be able to:

• List seven common wood frame wall problems.
• Describe how condensation causes rot in three sentences.

Give three causes of rot.

1. Condensation

2. Leakage through the walls or roof

3. Wood/soil contact

List three reasons for walls bowing or buckling.

1. The walls are too tall 
2. Bracing is missing 
3. Unexpected concentrated loads 
4. Damaged studs

_____ is the biggest enemy of houses. (one word)

Water

A wood frame wall with wood siding should stop _____ inches above grade. (Insert a number.)

8

6 for brick wall

Exterior walls on completed houses are rarely subject to racking because they have _____ finishes and/or _____ sheathing. (Insert your answers separated by a comma.)

exterior,interior

Interior wall cracks radiating up from the top of windows may mean - (three answers)

1. sagging lintels

2. foundation settlement

3. shrinkage of framing members

Missing fire stopping - (three answers)

1. is more common on balloon frame than platform construction

2. is a fire hazard

3. is tough to see on most inspections

Offset bearing wall - (two answers)

1. are common - often result in minor structural problems

2. must always be parallel to joists

Longer studs are more susceptible than conventional length studs to

bowing or buckling

Open concept homes are more likely than conventional homes to -

Rack

Where is condensation damage likely to be worst?

At bottoms of walls

Wall framing problems are often tough to identify because wall-framing details are usually concealed.

True

Structure Inspection Section#3 Wall System Quiz#3

You should have finished Study Session 2 before starting this study session. This Study Session covers wood frame walls.

The estimated completion time is one hour.

Objectives
At the end of this study session, you should be able to:

• Describe platform and balloon frame construction in one sentence each.
• Describe the difference between load bearing and partition walls in one sentence.
• Describe two types of loads that walls see in one sentence each.
• List three functions of sheathing.
• List four ways to prevent racking of walls.

List five differences between a bearing wall and a partition wall

1. Partition walls have no structural elements below 
2. Load bearing walls rest on foundations, beams or another wall system 
3. Ends of floor or ceiling joists rest on load bearing walls but not partition walls 
4. Load bearing walls often have a wall directly above. Non-load bearing walls are less likely to have this. 
5. Door openings in load bearing walls have lintels. Openings in partition walls do not need lintels.

List four ways to prevent racking of exterior wood frame walls. 1. Interior finishes such as drywall, plaster or plywood  2. Exterior sheathings  3. Panel-type sidings  4. Diagonal bracing List three functions of sheathing. 1. support the siding 2. stiffen the wood frame walls 3. help prevent wind and water entering the building What are girts? (Include their function, location and material.) Girts are horizontal wood braces installed between studs to prevent buckling. They are typically installed near the mid-point of the wall. What is the difference between waferboard and OSB? In waferboard, the pieces are randomly oriented. In oriented strandboard (OSB), the wafers are aligned, at least on the faces of the panel. When is sheathing not needed? Sheathing is not needed if the building is otherwise protected from racking and weather, and the siding needs no support. In _____ framing, the wall studs extend through the subflooring. balloon Studs with splices are - (two answers) weaker more common in partition walls All of these words mean the same thing except: sill plate top plate <selected answer> base plate bottom plate sole plate Loadbearing wall studs should have holes no larger than - 1/3 to 40% of width, depending on authority Adjacent pieces of plywood sheathing should be butted tightly to enhance weather-tightness. False Bearing walls and partition walls are built in substantially the same way. True Openings in partition walls need lintels. False Sheathing paper (building paper) should act as a vapor retarder. False Walls see vertical loads only. False

Structure Inspection Section#3 Wall System Quiz#2

You should have finished Study Session 1 and Quick Quiz 1 before starting this Study Session.

The estimated completion time is 45 minutes.

Objectives

• List six common problems with masonry walls in addition to cracks.
• List six causes of leaning, bowing or bulging brick walls.
• List seven causes of mortar deterioration.
• Describe corbelling in one sentence.

Briefly describe corbelling. How much can a masonry wall be corbelled before it may become unstable?

Corbelling is staggering bricks so that higher bricks project out beyond bricks below. A wall can be corbelled one-third of its thickness before becoming unstable.

List seven causes of deteriorated mortar.

1. weathering

2. poor quality mortar

3. a poor job of laying the mortar (too thin or thick, uneven, incomplete, etc)

4. the weather was too hot to lay brick

5. the weather was too cold to lay brick

6. the mortar set too long before being used

7. additives to the mortar affected its strength

List six common causes of leaning, bowling, or bulging masonry walls.

1. no lateral support

2. foundation movement

3. sagging or sloping floor system

4. rafter spread

5. failure of ties

6. expansion of bricks

What causes wavy brick walls?

The walls may have been laid up too quickly or the mason may have skimped on the amount of mortar on the back part of the bricks.

What is a common cause of bulging masonry walls below windows?

Leaking water at the window has rusted metal ties.

You see large metal plates or stars on the outside of the masonry walls at the top of the first floor level of an older two-story building. Why are these here?

Rods used to stablizing settling house

Which walls tend to expand over time, after original construction?

clay brick <selected answer>

concrete block

poured concrete

concrete brick

wood frame

Bricks laid on their sides forming windows sills are structural problem.

False

Hollow concrete blocks are weaker if laid on their side

True

Patched cracks on brick are a sure sign of serious structural movement.

False