SEARCH · Engineering Papers

Results for “PAINT”

Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.

SourceResearch connectionFrom yearThrough year

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 901 records · Page 50

All sources NASA NTRS DOE OSTI

DOE OSTI2022

Wastewater Recycling Using a Hygroscopic Cooling System

This project by the Energy & Environmental Research Center (EERC), Baltimore Aircoil Company (BAC), and Great River Energy (GRE) evaluated the concept of recycling wastewater at a coal-fired power plant using a hygroscopic cooling system, which is an evaporative cooling technology analogous to conventional cooling towers, except that sparingly soluble dissolved solids are precipitated and removed as waste solids instead of purging them with a liquid blowdown stream. This technology can maximize the use of plant makeup water by obtaining useful evaporative cooling from wastewater while minimizing the volume of wastes needing disposal. Experimental activities were conducted in two phases, a laboratory-based evaluation of the properties of wastewater from the host site, GRE’s Coal Creek Station near Underwood, North Dakota, and a field test of a small pilot hygroscopic cooling system at the host site power plant. Findings from the laboratory study informed the design of the pilot system and the system’s field test performance served as the basis for a techno-economic analysis (TEA) of the hygroscopic recycling concept. At the preferred operating conditions identified during the TEA, the wet-bulb approach temperature of the tower was 7.3°C (13°F) and the volume of blowdown produced by the plant was reduced to 5.4% of its incoming volume. Waste solids produced during field testing were classified as nonhazardous waste based on the measured hazardous element content and evaluation of their leaching potential. However, to qualify as a solid for landfill disposal i.e., as determined by the U.S. Environmental Protection Agency’s paint filter test, it appears that a dewatering step beyond hydrocyclone separation is needed. The baseline levelized cost of wastewater disposal (LCWD) for hygroscopic wastewater recycling was estimated to be $\$ $3.69–$\$ $3.72 per m3 of plant blowdown. Capital cost was estimated to contribute over 54% to the LCWD, and parameters that impact capital cost such as the heat exchange coil material of construction and the tower’s wet-bulb approach temperature were identified as having the greatest impact on overall LCWD. A LCWD estimate prepared for the same application but using thermomechanical brine evaporation was almost 40% higher than that calculated for hygroscopic cooling, despite recovering distilled-quality water for reuse, while the LCWD for disposal-only, deep well injection was estimated to be 30% lower compared to hygroscopic wastewater recycling.

01 COAL, LIGNITE, AND PEAT↗

DOE OSTI2022

Design of Transition-Metal/Zeolite Catalysts for Direct Conversion of Coal-derived CO 2 to Aromatics

This project introduces a lab-scale, stand-alone process to produce aromatics from CO 2 . Besides reducing the amount of coal-derived CO 2 emission, this process can provide new approaches to produce valuable chemicals such as benzene, toluene, and xylene (BTX). These chemicals are the starting material in various industries such as pharmaceuticals, polymers, paints, and coatings. The focus of the project is on developing a suitable reaction configuration, feed composition, and catalyst combination that leads to high aromatics selectivity and CO 2 conversions. To achieve these objectives, computational catalysis will accompany hands-on experiments to provide insights to potential transition metals or alloys that may serve as optimal active sites for different steps of the reaction mechanism, such as reduction of CO 2 and dehydration (in the case of alcohol intermediates) and oligomerization (in the case of paraffins or olefins) of intermediate hydrocarbons.

01 COAL, LIGNITE, AND PEAT↗

DOE OSTI2022

SRPPF Aqueous Recovery System Sorbent Testing

This study details preliminary testing of 7 inorganic sorbents for the solidification of the surrogate SRPPF aqueous recovery system liquid excess material of 4M sodium nitrate. Sorbents were subject to various mixing methods to incorporate sodium nitrate solution including static, rotating, and in situ paddle mixing. Paddle mixing was found to be the most effective mixing technique, while simple static tests were also successful, though only for some of the sorbents. Setting tests were performed to ensure that the sorbent sequestered the liquid without release through a conical paint filter. Recommended set times ranged from near immediate to 7 days. The set mixtures were investigated further using ultra-centrifugal liquid release testing, thermogravimetric analysis, and visual microscopy to understand the mechanism by which the sorbent sequestered the liquid. Most sorbents seem to incorporate liquid by sorbing it onto and into the sorbent particles, while Drierite ® , anhydrous calcium sulfate, created a crystal structure that bound the surrogate liquid. Overall, four sorbents are recommended for continued testing: Aquaset II, Aquaset IIG, Drierite ® , and Spill-X-A.

12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE W↗

DOE OSTI2022

Enhancing Lifetime and Reducing Costs for Fish Diversion Netting Structures (Abstract)

This effort will focus on technology transfer and commercialization of antifouling coatings with an enthusiastic and engaged industrial team. Environmental requirements and operational demands call for a nontoxic coating/paint to prevent fouling on fish passage guidance netting at hydropower facilities. For example, one netting customer estimated the capital cost for compliance at $\$12$ million to $\$15$ million. This project will build partnerships between PNNL and private companies to optimize, demonstrate, mature, and commercialize a novel PNNL-developed technology that addresses this critical coating need of the hydropower industry. This effort will support modification of existing coatings for application to flexible netting structures. Industrial partners include commercial coating development specialist (Lorama), hydrophobic material manufacturer and paint developer (Dry Surface Technologies), aquatic applications specialists (Prometheus Innovations and River Connectivity Systems), and hydropower netting producer (Pacific Netting Products). Engagement with the U.S. Army Corps of Engineers (USACE) and Bureau of Reclamation (BOR), two hydropower operators, throughout the project will provide expertise and field test sites that will provide crucial proof of real-world performance data (additional details provided in Teaming section). Taylor Shellfish Farms will provide organisms and fouling expertise as well as a perspective of potential broader impacts for the blue economy. Sample netting will demonstrate performance in a range of environments for key hydropower applications. PNNL will work with industrial partners to overcome commercialization barriers as well as resolving any manufacturing or regulatory issues. This Phase 1 effort is focused on technology optimization for application to fish passage guidance netting and technology validation as verified by independent testing (through USACE, BOR, Taylor Shellfish and Prometheus Innovations). Through this effort, SLIC will be demonstrated for netting applications at technology readiness level (TRL) 5. The field test data will allow optimization of SLIC formulation and performance which is key to enabling technology transfer of a mature proven technology to industry and production of a viable commercial product specifically focused for hydropower needs.

13 HYDRO ENERGY↗

DOE OSTI2022

Design of Transition-Metal/Zeolite Catalysts for Direct Conversion of Coal-derived CO 2 to Aromatics

20 FOSSIL-FUELED POWER PLANTS↗

DOE OSTI2023

Perspectives on the status of fusion energy research and near term directions [Slides]

Over the past few years, nearly five billion dollars of private investments from private industry sparked excitement for accelerating the development of fusion energy technologies. Driving these investments are various technical advances in research such as those at facilities such as JET, EAST, NIF, etc. At the same time, the Office of the President, in the spring of 2022, announced a commitment to fusion energy development as part of its strategy to combat climate change. With the goal of a pilot power plant by the 2040s, the research strategy shifted to public private partnerships as a means for the government to support the lofty goal of shorten the deployment time of fusion energy technologies. The rapid change in strategy created a quickly changing research landscape with many potential opportunities. In this presentation, I will attempt to paint a picture of the current state of fusion energy, highlight major challenges, and provide insights into some near-term opportunities for LANL.

70 PLASMA PHYSICS AND FUSION TECHNOLOGY↗

DOE OSTI2024

Hidden in Plain Sight: How Interior Furnishings Management Can Help Los Alamos National Laboratory Meet the United States Department of Energy's Sustainability Goals [Capstone Project]

In the last three years, LANL has purchased over $50 million in new interior products with a focus on sustainable building and high-quality interior furnishings, carpet, and paint. Purchasing interior products that focus on sustainable manufacturing, however, is only the beginning of properly operating and maintaining an interior space over its useable life. Sustainable commercial furniture, if well maintained and warrantied, can last well beyond the accounting depreciation of the asset, ultimately saving taxpayer dollars. Given DOE’s recently announced built environment sustainability goals, now is the time to look at interior products as an important part of the overall sustainability plan for LANL’s green building initiatives. The scope of this thesis provides an environmentally sustainable O&M process for the procurement, use, and proper decommissioning of interior products. The thesis also provides environmental and financial data to assist with LANL’s overall DOE Matrix milestones, currently due in 2030.

32 ENERGY CONSERVATION, CONSUMPTION, AND UTILIZATI↗

DOE OSTI2023

Laser Driven Hydrothermal Processing (LDHP) for Rapid Dissolution of Glassy Nuclear Debris

Discovered in 2009 on the SLAB laser system at LLNL, Laser-Driven Hydrothermal Processing (LDHP) both spalls and transiently dissolves a wetted surface (e.g., rock, concrete, paint) when that surface is struck by a laser beam pulse under specific conditions. Previous projects have explored the application of LDHP to expediting sample dissolution for post-detonation nuclear forensics. Early results were very promising, indicating that this method could decrease material dissolution time by a factor of 10 or more. However, the large and complicated lasers previously used are impractical for this application. Under the R^3 venture we aimed to benchmark the LDHP capabilities of turn-key commercial off-the-shelf (COTS) lasers, and to establish how this process could be integrated into an analytical workflow for nuclear forensic analysis. We demonstrated that geological rock standards could be quickly processed into fine powder by LDHP followed by complete acid digestion in 15 minutes, without elemental fractionation that would skew analytical results. We determined that the COTS laser can be used for LDHP that could potentially reduce dissolution time for solid nuclear debris samples in post detonation nuclear forensics. One downside to this approach, however, is that the laser interactions are different with every material, so extensive method validation would be required for all likely material compositions. The LDHP processing rates of several materials were tested and determined to be favorable in the beginning with significant slowdown due to particulate scattering. This could be mitigated either by stopping and centrifuging the sample at specific intervals, or through design of a continuous solvent flow through mechanism.

36 MATERIALS SCIENCE↗

DOE OSTI2024

Degradation and Upcycling of Poly(acrylic) Acid (PAA)

Poly(acrylic acid) (PAA) is a superabsorbent polymer (SAP) widely used in food, paint, textiles, and household products, such as absorbent hygiene products. Specifically, disposable diaper waste comprises a large majority of hygiene waste, in which 80% is landfilled and 20% is incinerated. This proposal describes new methods to valorize PAA to mitigate pollution and risk of large-scale release, dispersion, and accumulation of PAA into aquatic and terrestrial environments. The first strategy builds upon photoredox catalysis to oxidize PAA, which will allow for subsequent cleavage to PAA into valuable chemical feedstocks with intriguing functional groups that can readily undergo further transformations. Moreover, in conjunction with RAFT polymerization, photoredox catalysis would also lead to preparation of new graft block polymers to serve as pH-sensitive drug delivery vehicles. The second strategy invokes electrocatalysis, which can access different intermediates compared to photoredox catalysis. This method would lead to refunctionalization and repurpose of PAA into hydrogels and zwitterionic polymers that can find utilities in ion exchange, water treatment, soil conditioning, paper reinforcement, pigment retention, shampoo formulation, and drug delivery.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗

DOE OSTI2025

Testing a Hazmatpac Can with Locking Ring as a Secondary Shipping Container for Radium-224/Lead-212 Generators

A Hazmatpac can, paint can style shipping container with locking ring, was tested for use as an alternative shipping configuration for shipment of radium- 224 /lead- 212 generators. 224 Ra ( t 1/2 = 3.63 d) decays by alpha emission to radon-220 ( t 1/2 = 55.6 s). The potential for the radioactive radon gas to escape the generator column and the shipping container is of particular concern for the safe delivery of 224 Ra/ 212 Pb generators to customers. The purpose of this study was to evaluate whether the Hazmatpac can is a suitable shipping configuration, capable of containing the radon gas that may escape the generator column during transit. A 17.3 mCi 224 Ra/ 212 Pb generator was built and packaged into a Hazmatpac can. The can was smeared by a Radiological Control Technician (RCT) every day for seven days to analyze for radioactive contamination on the outside of the can. Over the course of the study, no radioactive contamination was found on the outside of the can. Therefore, the Hazmatpac can was approved as an alternative shipping configuration for shipment of 224 Ra/ 212 Pb generators.

11 NUCLEAR FUEL CYCLE AND FUEL MATERIALS↗

DOE OSTI2021

Next Generation Co-Molded One-Piece Automotive Parts

The purpose of this project was to determine the feasibility of co-molding Class A Sheet Molding Compound (SMC), structural SMC, and continuous fiber prepreg materials to produce a single piece co-molded automotive part, such as a hood. The combination of the three molding materials and the incorporation of selective design features (ribs, flanges, corrugations) was expected to eliminate the need for inner reinforcement panels, significantly reducing tooling costs and simplifying the manufacturing process. A multi-material solution would also result in significant weight savings. The scope of this project included the material characterization of the three materials, development of cure and flow simulation models, and validation of the models against parts molded with different combinations of the materials on an 11”x11” plaque tool with rib features. The intent of this project was to apply the learnings obtained from co-molding a part with simplified geometry to a Phase 2 project that would produce a single piece hood, co-molded with the same materials. Resins from INEOS Composites were provided to IDI to produce SMC and continuous fiber prepregs. Purdue University and INEOS Composites characterized the rheological and curing behavior of the different materials as well as the mechanical properties of the co-molded parts. This data was used by Purdue University to create simulation models. Models were created to predict both flow patterns and predict mechanical properties of different laminate constructions in and around the ribs. Michigan State University - Corktown validated Purdue’s models by co-molding the three materials in different combinations on a tool containing rib features provided by Century Tool. The co-molded parts were evaluated against the simulation models by Purdue, Corktown and INEOS. The project team demonstrated the following: • The ability to obtain a cohesive co-molded structure made up of Class A SMC, Structural SMC, and continuous fiber prepreg. • The ability to obtain a co-molded part with a Class A surface • Modeling of flow and fiber orientation • Modeling to predict mechanical properties of multi-material co-molded structures The predicted flow behavior and fiber orientation from simulations were then compared with the molded samples. Exact local orientation state was difficult to compare between microscopy and flow simulation, but captured general trends. Multi-material flow behavior was generally modeled well with SMC materials, but the introduction of woven material sheets requires further model development. Purdue compared the predicted versus actual mechanical properties, and INEOS Composites evaluated the surface appearance of unpainted and painted co-molded parts. The models developed by Purdue demonstrated that the mechanical properties can be predicted for parts with varying material configurations. The resulting models can be applied to future co-molded part design, tooling design, and molding conditions.

36 MATERIALS SCIENCE↗

DOE OSTI2025

TEAMER Technical Support on Biofouling and Corrosion for E-Wave Technologies LLC Novel (Abstract)

National Technology & Engineering Solutions of Sandia (NTESS) in collaboration with the Pacific Northwest National Laboratory (PNNL), and with guidance from E-Wave, will assess corrosion and biofouling challenges specific to E-Wave’s innovative WEC designed to retrofit into and power existing aquaculture farm infrastructure from ocean waves. The teams will examine coatings via a static raw seawater test and determine the efficacy of coatings for E-Wave’s applications. Samples will include panels of materials provided by E-Wave and coated with three different paint treatments. Fouling will be determined using a staining technique followed by photographic analysis to evaluate fouling intensity on the surface. Materials will also be weighed before and after submersion to facilitate weight change analysis resulting from fouling organisms aggregating on the materials.

16 TIDAL AND WAVE POWER↗

DOE OSTI2025

Applied Research and Development to Support Open Water Testing at PacWave – Task 5: Development of additively manufactured, functionally graded, corrosion resistant clads for wave energy applications

In this task, we focused on developing corrosion-resistant claddings for wave energy applications. Wave energy systems are exposed to saline conditions, which are corrosive to many metallic structural materials (e.g., carbon steel). Corrosion-resistant (stainless) steels are typically alloyed with >18% chromium (Cr) and >8% nickel (Ni), which dramatically raises material costs and can hinder the development of wave energy systems; thus, coatings are a necessary corrosion protection method for most. Non-metallic coatings (paint, epoxy) have shorter service lives, limited resistance to mechanical stress and wear, plus additional costs of inspection and eventual replacement. Therefore, overlay stainless steel (SS) claddings have a cost-effective use case for protecting components from corrosion, particularly for those that may be subject to mechanical stress / wear and with long service lives.

16 TIDAL AND WAVE POWER↗

DOE OSTI2025

The Snow Albedo Evolution (SALVO) Campaign at the North Slope of Alaska Field Campaign Report

The springtime surface-albedo transition in the Alaskan Arctic, along with the forces that determine its duration and nature, was the focus of the Snow ALbedo eVOlution (SALVO) campaign. The SALVO team investigated the reasons and durations of the stages of spring melt, during which albedo values decrease from 0.8 to 0.1, signifying the year’s largest and most significant radiative energy change. SALVO II (2022, 2024) built on findings from the successful SALVO I (2019) melt season campaign and previous research on the melt transition period conducted by Grenfell and Perovich (2004). SALVO used the ARM NSA observatory, thus aligning with a core principle of the ARM Decadal Vision to “provide comprehensive and impactful field measurements to support scientific advancement of atmospheric process understanding.” SALVO fieldwork was conducted in the spring near the ARM NSA Central Facility in Utqiagvik, Alaska (Figure 1). Comprehensive data sets were collected in 2019, 2022, and 2024, which included spectral and broadband albedos, snow and meltwater depths, snow stratigraphy, snow grain size data, and aerial imagery. In April of each project year, before the snow began to melt, we established survey lines at three or four locations: inland tundra at NSA E12, coastal tundra at the NSA C1 site, Elson Lagoon, and offshore on the Chukchi Sea sea ice (2022 only). We set up a 200-meter-long line, marked every five meters, to enable repeated measurements of surface albedo and snow depth at each location. During most site visits, the SALVO II team dug at least one snow pit to assess the characteristics of the vertical snow layers, including the types and sizes of snow grains, snow density, and the distribution of liquid water. We evaluated the characteristics of flowing or pooled water at the bottom of the snowpack. Watching snow melt in the Arctic has been compared by some to being as exciting as watching paint dry, but it is far more exciting and dynamic than that. Initially, changes happen slowly while the snow cover remains above 80%, but then reductions in the albedo of the landscape, from about 0.8 to 0.4, combined with rising spring temperatures, begin to accelerate the melt. It happens so quickly that no matter how hard the field team works, they cannot keep up with documenting the changes. At first, liquid water is scarce—only a few wet layers of snow in the snowpack. But then, water becomes ubiquitous, transporting melt energy and creating an extremely heterogeneous albedo and melt landscape. At the end of each field season, the SALVO team is exhausted, relieved to see the snow gone, and joyful to play in the melt ponds on the sea ice under the midnight sun. Overall, the 2024 SALVO field campaign was a highlight, reflecting numerous lessons learned from 2019 and 2022. Daily measurements were taken more than 10 times at each site, resulting in a comprehensive time series of snow conditions and albedo. The team deployed using snowmachines and then on foot when snowmachine travel was no longer permitted on the melting tundra. Instrument mounts and packaging were optimized for quick deployment, regardless of the mode of transportation.

54 ENVIRONMENTAL SCIENCES↗

DOE OSTI2019

Response of Jointed-Structures in a Shock Tube: Simultaneous PSP and DIC with Comparison to Modeling

Experiments, modeling and simulation were used to study the nonlinear dynamics of a jointed-structure in a shock tube. The structure was a full-span square cylinder with internal bolted connections excited by fluid loading. The width-based Reynolds number was ≈10 5 . The cylinder was exposed to an impulsive force associated with the incident shock followed by transverse loading imposed by vortex shedding. In the experiment, aerodynamic loading was characterized with high-speed pressure sensitive paint (PSP). Digital image correlation (DIC) concurrently measured the structural response. The maximum displacement occurred when the vortex shedding frequency most closely matched the structural mode of the beam associated with a rocking motion at the joint. A finite element model was developed using Abaqus, where the nonlinear contact dynamics of the joint were simulated using Coulomb friction. The PSP data loaded the model and the interaction was treated as one-way coupled. The simulations well-matched the trends observed in the experiment. Overall, the root-mean-square values of the transverse displacement agreed to within 24% of the experiment. The modeling showed rocking about the joint during vortex shedding was critical to the nonlinear damping and energy dissipation in the structure. We conclude this campaign highlights the importance of jointed-connections to energy dissipation in structures under aerodynamic loading.

42 ENGINEERING↗

DOE OSTI2021

Osur_paper

Glyphosate is widely used as a herbicide, but recent studies begin to reveal its detrimental side effects on animals by targeting the shikimate pathway of associated gut microorganisms. However, its impact on nutritional endosymbionts in insects remains poorly understood. Here, we sequenced the tiny, shikimate pathway encoding symbiont genome of the sawtoothed grain beetle Oryzaephilus surinamensis. Decreased titers of the aromatic amino acid tyrosine in symbiont-depleted beetles underscore the symbionts’ ability to synthesize prephenate as the precursor for host tyrosine synthesis and its importance for cuticle sclerotization and melanization. Glyphosate exposure inhibited symbiont establishment during host development and abolished the mutualistic benefit on cuticle synthesis in adults, which could be partially rescued by dietary tyrosine supplementation. Furthermore, phylogenetic analyses indicate that the shikimate pathways of many nutritional endosymbionts likewise contain a glyphosate sensitive 5-enolpyruvylshikimate-3-phosphate synthase. These findings highlight the importance of symbiont-mediated tyrosine supplementation for cuticle biosynthesis in insects, but also paint an alarming scenario regarding the use of glyphosate in light of recent declines in insect populations.

59 BASIC BIOLOGICAL SCIENCES↗

DOE OSTI2016

Field Testing Unvented Roofs with Asphalt Shingles in Cold and Hot-humid Climates

BSC TO5 Task 7.1 Field Testing Unvented Roofs with Asphalt Shingles in Cold Climates - Bolingbrook, IL 60440 BSC TO5 Task 7.1 Field Testing Unvented Roofs with Asphalt Shingles in Hot-Humid Climates - Friendswood, TX 77546 To understand the long-term moisture performance of unvented roof assemblies with fibrous insulation, the U.S. Department of Energy's Building America team Building Science Corporation built and monitored test roofs in two climates: a cold-climate test house in Bolingbrook, Illinois (Chicago area; zone 5A), and a hot-humid test house in Friendswood, Texas (Houston area, zone 2A). The Chicago-area test bed had seven parallel experimental rafter bays. The assemblies included a control vented compact (cathedral) roof, a dense-pack cellulose unvented roof, and an unvented roof with a "diffusion vent" (a strip of vapor-permeable gypsum sheathing at the ridge to allow drying). The interior finish was gypsum wallboard (GWB) with latex paint. The other four bays were top vent roof assemblies, which have a polypropylene breather mesh between the roof sheathing and the asphalt shingles to allow ventilation drying of the assembly from underneath the vapor-impermeable shingles. Two of the four "top vent" roofs were fiberglass batt and two were dense-pack cellulose roofs with either interior GWB or open to the interior. Wintertime moisture-related failure was accelerated by providing interior humidification (22.2 degree C [72 degree F]/50% relative humidity [RH]), which is known to be an extreme interior loading). Data were captured over 8 months, including a winter and the following spring and early summer.

Array↗

DOE OSTI2016

Spray Foam Exterior Insulation with Stand-Off Furring - New York

IBACOS and Green Homes America 1 (GHA) collaborated with the New York State Energy Research and Development Authority (NYSERDA) Advanced Buildings Program to research a variation of a commercial curtain wall assembly for residential construction as part of a comprehensive whole-house deep energy retrofit (DER) package. The advantages of this strategy include minimizing the physical connections to each individual existing wall stud, using closedcell spray foam to encapsulate existing siding materials including lead paint, and creating a vented rain screen assembly to promote drying. As Moore (2011) states, "Closed-cell foam acts as air-sealing, insulation, and secondary drainage plane..." Field installations on a limited number of houses indicate that the incremental cost when installed as part of a typical siding and window replacement job adds approximately $10/ft2 of wall area. 2 x 4 framing members were attached to the wall at band joists and top plates using "L" clips, and spray foam was used to insulate the wall after the framing was installed. Windows were installed as the framing was put up, including extension jambs. Key lessons learned include the following: (1) The installed cost of the spray foam system was comparable to the installed cost of the rigid foam and furring strips. (2) Spray foam should be applied in such a way that it locks the framing members in place before the remaining foam is installed in the field of the wall. The spray foam has a tendency to move the new wall framing as it expands. Best practice is to "picture frame" the wall framing with spray foam and then apply the spray foam in the field of each bay. (3) Variations in the existing siding conditions must be accounted for when attaching the ledger boards and wall framing. A best practice is to uniformly shim the ledger boards off the walls so the new framing is a uniform distance from the ledger boards and the inside surface of the interior framing. This is important primarily for window and door installation and the associated extension jambs and trim. (4) From a sequencing perspective, it is advantageous to replace the windows at the same time as the exterior walls are being built. This requires a crew that can perform a number of different tasks (e.g., framing, flashing, window install, trim carpentry) and does not lend itself to subcontracting this approach piecemeal (e.g., framing subcontractor, window installer, drainage plane installer, trim carpenter). (5) Application of the brackets and associated fastener screws was more time consuming than anticipated. (6) It is important for the spray foam contractor to perform all preparatory work, which in this case included placing plastic over the windows and exposed foundation to minimize or eliminate the possibility of damage due to overspray.

Array↗