Start with the opening drawing note of the issued Section 07 21 16: confirm that the drawings show each insulated location with its R-value, the vapor retarder location where one is required, and the size and location of attic and cathedral ceiling ventilation openings. Then check that the type and facing kept suit each location and its exposure, that the vapor retarder side follows the project moisture analysis and does not double up with a faced blanket or a retarder in another section, that eave blocking and the clearances at recessed lights, chimneys, and flues appear in the details, and that floors, pipes, wiring, and access panels are addressed where the drawings show them.
Assemble the review package
Gather the wall, roof, ceiling, and floor sections with the insulation layer and R-value at each, the building sections through attics and cathedral ceilings with the ventilation path, eave vents, ridge or gable vents, and the air space above the insulation, the roof plan with vent sizes and counts, the reflected ceiling plans with recessed light fixtures, attic access doors, and access panels, the mechanical and plumbing plans with flues, chimneys, gas or oil appliances, and piping in exterior walls and attics, the floor framing over crawl spaces or unheated spaces, the partition types where blankets are used for sound control with their STC ratings, the energy compliance documents and the moisture analysis the vapor retarder decision rests on, the existing conditions survey for retrofit work, and the issued Section 07 21 16 with Sections 07 21 13, 07 21 23, 07 27 10, 09 29 00, and 09 90 00. Follow one exterior wall, one attic, and one floor from the framing to the interior finish before assuming the others match.
WBDG publishes UFGS 07 21 16: Mineral Fiber Blanket Insulation as a public guide-specification reference (accessed November 12, 2026). Use your project’s issued specification and amendments for the actual comparison; the guide specification does not automatically govern your project. The checklist below is an original suggested review workflow, not a reproduction of the UFGS requirements.
Eight checks to run against the issued set
Use one record per location or system. The CSV contains the same eight prompts plus fields for source revisions, observed evidence, the review owner, the decision, and closure references.
| Check | Sources to compare | Question to resolve |
|---|---|---|
| What the drawings must show | Opening drawing note (insulated locations, R-value at each, vapor retarder location, attic ventilation openings) + Blanket Insulation R-value note and sentence (R-value as indicated on the drawings) + Attic Ventilation note (net ventilation by attic floor area, with or without a vapor retarder; cathedral ceiling air space and bottom and top vents shown on the drawings) + wall, roof, ceiling, and floor sections + roof plan | Does every insulated wall, ceiling, roof, and floor type carry an R-value on the drawings, since the article has none of its own, is the vapor retarder shown wherever the project requires one, and do the roof plan and building sections size and locate the attic vents and, for each cathedral ceiling, show the ventilation air space, its depth, and the vents at its bottom and top, as the notes ask? |
| Type, facing, and surface burning by location | Blanket Insulation article (ASTM C665 Type I unfaced, Type II non-reflective facing, Type III reflective facing; Class A or B; a bracketed flame spread limit introduced by “except”, with an optional smoke developed limit) + Fire Safety note (combustible facings and binders not left exposed in accessible spaces; UFC 3-600-01 and the local code) + Blocking article (unfaced Type I blankets) + sections and finish schedule | Has the specifier kept only the types the drawings use and tied each to a location, are faced blankets kept out of attics, crawl spaces, and service spaces where the facing would be left exposed, unless a covering is drawn, and since the sentence offers Class A with one flame spread limit and then an “except” bracket that allows a higher one, which limit governs, and has the inch-pound critical radiant flux for Class B been given the time unit it lacks? |
| Vapor retarder: whether, which side, and which product | Vapor Retarder notes (moisture analysis under UFC 3-101-01; a much lower permeance may be needed; paint or foil-faced gypsum board as alternatives specified elsewhere, with this section’s retarder paragraphs deleted; use only where the analysis shows a need) + Vapor Retarder article (polyethylene sheet or a membrane whose metric permeance is fixed while the inch-pound value is a blank) + Pressure Sensitive Tape (not bracketed) + affixed and separate retarder installation paragraphs + Sections 07 27 10, 09 29 00, and 09 90 00 | Do the sections show the retarder on the side the moisture analysis supports, and only one retarder per assembly, whether it is a blanket facing, polyethylene, foil-faced board, paint, or the air barrier, is the permeance stated in one consistent value, since the membrane row fixes the metric value and leaves the inch-pound value blank, and where the retarder moves to paint or board, have the retarder paragraphs and the tape and its submittal been deleted here? |
| Attic ventilation and blocking at eaves and attic doors | Blocking at Attic Vents and Access Doors (permanent blocking to keep insulation off eave vents; bracketed blocking at attic trap doors and at equipment that needs maintenance) + Special Requirements for Ceilings (do not block soffit vent airflow; insulation fixed to the attic door) + Attic Ventilation note + eave and soffit details + roof plan | Do the eave details show a permanent baffle or blocking that holds the blankets clear of the soffit vents and keeps the ventilation path open above them, is the attic access door insulated and blocked around, are the equipment and controls in the attic given a blocked access path, and does the net vent area on the roof plan match what the note asks for, given whether the ceiling has a vapor retarder? |
| Clearances at recessed lights, chimneys, flues, and appliances | Blocking Around Heat Producing Devices items (recessed fixtures not rated for insulation contact; masonry chimneys; vents, connectors, and other chimneys to NFPA 211; gas appliances to NFPA 54; oil appliances to NFPA 31) + blocking exemption (blanket and attached facing that pass ASTM E136, or chimneys listed for insulation contact) + Blocking article (noncombustible blocking per ASTM E136) + existing conditions note + reflected ceiling plans and fixture schedule + mechanical flue details | Are the recessed fixtures in insulated ceilings scheduled as rated for insulation contact, or does the ceiling detail show the noncombustible blocking and clear space above them, do the flue and chimney details through insulated ceilings show the clearance or a listed zero-clearance product, and where the exemption for noncombustible blankets is relied on, are the facings noncombustible too? |
| Continuity at framing, bridging, pipes, and wiring | Continuity of Insulation (tight to framing and obstructions; bracketed full-width blankets across the top of shallow joists; corners and wall-to-ceiling joints; avoid thermal bridges) + Installation at Bridging and Cross Bracing and its note (unfaced blankets only; separate retarder if needed) + Cold Climate Requirement and note (insulation outside the pipes, by ASHRAE climate zone) + Electrical wiring and ceilings paragraphs + Sizing of Blankets + wall and ceiling sections | Where the required R-value is deeper than the ceiling joists, do the sections show the cross layer the bracket provides for, where floor or ceiling framing has bridging, are unfaced blankets and a separate retarder specified, do the exterior wall sections in colder climate zones place the water piping on the warm side of the insulation, and are corners and wall-to-ceiling junctions drawn without gaps at the top plate? |
| Floors, sill sealer, and access panels | Special Requirements for Floors (corrosion-resistant wire mesh, wire fasteners, or lacing) + Wire Mesh and Mechanical Fasteners + Sill Sealer note (foundation-to-sill air leakage; window and door frames) and article and installation (sill on foundation wall or slab edge only) + Access Panels and Doors (blanket on panels above a size threshold; same R-value) + floor framing sections + crawl space and foundation details + Section 08 31 00 | Do the floor sections over crawl spaces and unheated spaces show how the blankets are supported, and is the support material suited to a damp crawl space, where sill sealer is kept, do the foundation details show it under the sill plate, and since the note also suggests it at window and door frames but no installation paragraph covers that use, which product seals those frames, and do the access panels in insulated floors and ceilings carry insulation to the same R-value? |
| Sound blankets, indoor air quality, and submittals | Sound control note (density, material, and thickness from acoustic analysis; blanket chosen thicker than the wall cavity; edit the section) + Certifications (Insulation Products, not bracketed) and Reduced VOC paragraph and SD-07 item (bracketed; note on confirming certified mineral wool) + Recycled Materials and Energy Star + Adhesive emissions + SD-03 and SD-08 + partition types with STC ratings | Where partition types call for sound attenuation blankets, has the specifier added the density, material, and thickness the note says come from acoustic analysis, since no article covers them, and do the partition STC ratings rely on that product, and since the Insulation Products certification is unbracketed while the VOC paragraph and its submittal are bracketed for mineral wool, does the issued section require the indoor air certification for the product the project will actually use? |
Worked example: an attic with no baffles, faced batts over bridging, and two vapor retarders
Illustrative example: a renovation of a wood-framed family housing unit in a cold climate zone adds blanket insulation to the attic floor, the exterior walls, and the floor over a vented crawl space. The attic section shows batts deeper than the ceiling joists in a single layer, no eave baffle, and recessed downlights that the fixture schedule does not identify as rated for insulation contact; a metal flue passes through the ceiling with no clearance detail. The wall section shows kraft-faced batts, and the interior finish is foil-faced gypsum board specified in Section 09 29 00. The floor framing has cross bridging, and the floor section shows faced batts with no means of support. The issued Section 07 21 16 keeps Types I and II, keeps the Class A option with the higher flame spread choice in the “except” bracket, keeps the vapor retarder article and tape, and keeps the cold climate paragraph, while the plumbing plan shows supply piping in the exterior wall outboard of the batts.
Ask the architect to add a cross layer above the ceiling joists, eave baffles that keep the vent path open, insulation-contact rated fixtures or noncombustible blocking at the downlights, and a clearance detail or listed product at the flue; to pick one vapor retarder for the walls, the batt facing or the foil-faced board, as the moisture analysis supports; and to show unfaced blankets on wire mesh or lacing in the crawl space floor with a separate retarder if one is needed. Ask the plumbing engineer to move the supply piping to the warm side of the insulation, and ask the specifier to state which flame spread limit governs and to resolve the bracketing of the indoor air quality certification.
Avoid a false conflict
Section 07 21 16 covers mineral fiber batts and blankets fitted between framing. Board and block insulation in walls follows Section 07 21 13 and the wall insulation guide, blown and poured fill follows Section 07 21 23 and the loose fill guide, roof insulation boards under low-slope membranes follow Section 07 22 00 and the roof insulation guide, pipe, duct, and equipment insulation follows Section 23 07 00 and the mechanical insulation guide, the air barrier follows Section 07 27 10, and foil-faced gypsum board or vapor-retarder paint follow Sections 09 29 00 and 09 90 00, so check those before calling a requirement missing. Some of the section’s own wording needs resolving: the Insulation Products certification is not bracketed while the VOC paragraph and its submittal are, the Blanket Insulation sentence offers Class A with one flame spread limit and then an “except” bracket that allows a higher one, the Class B critical radiant flux lacks a time unit in inch-pound, and the membrane permeance is fixed in metric but blank in inch-pound. Ask the specifier which wording the project intends before treating a difference as a design conflict.
When requirements disagree, follow the project’s document-control and clarification process. Do not assume that drawings always override specifications, or the reverse. Identify the exact sources and request an authorized decision.
Close the issue across the affected documents
Record the location or tag, drawing and specification references, issue dates, observed difference, and the decision needed. Assign an owner and keep the item open until the response identifies the governing requirement. Check the revised drawings and specification references together; a response email alone may leave the issued package inconsistent.
For the overall process, use the guide to drawing and specification conflicts. Mark an inapplicable checklist row with a reason, and distinguish a verified correction from a question that still needs design information.
Where Groundbook fits
Groundbook’s drawing and specification review helps investigate potential disagreements in the documents you supply. Include the relevant specification sections and drawing references, then verify the cited evidence with the responsible reviewers before acting on a finding.