The online attic roof calculator will help you calculate the angles of inclination of the ridge and side slopes of the roof, the number and minimum cross-section of rafters, the volume of sheathing and materials that will be needed to construct the roof. Before designing an attic floor, read SNiP 2.08.01-89 “RESIDENTIAL BUILDINGS”.
The calculations of this calculator take into account the parameters given in TKP 45-5.05-146-2009 and SNiP “Loads and Impacts”.
A mansard (also sloping, sloping) roof is a roof that has two slopes with different angles tilt on each side. This technique helps to optimize the space under the roof and create a comfortable room under the roof (attic or attic floor). Similar roofs have been known since the 17th century. Today, the attic roof has many varieties. The attic can contain both utility and residential premises.
Mansard roof can be built either at the first stage of construction or added to an already completed building. Thus, the building can have more living space without the need to build a full second floor.
When building an attic roof, you need to take into account its specifics: steep slopes side slopes require increased costs for roofing. Also, the attic floor needs larger windows and additional thermal insulation, especially if the premises in it are intended for living.
By filling out the fields of the calculator, you can check the additional information, marked with an icon.
At the bottom of this page you can leave feedback, ask your own question to the developers, or suggest an idea to improve this calculator.
Explanation of calculation results
Angle of inclination of side rafters
The side (steeper) rafters and the side slope of the roof are inclined at this angle. The calculator not only takes into account the angle you specify, but also determines how compatible it is with the roofing material you choose. To change the angle of the slopes, you need to change the Laying Width (A1, A2) or the Height of the Rise (B1, B2).
Angle of inclination of ridge rafters
The upper (hanging) rafters and the upper (sloping, ridge) slope of the roof are inclined at this angle. The calculator not only takes into account the angle you specify, but also determines how compatible it is with the selected roofing material. To change the angle of the slopes, you must change the Laying Width (A1, A2) or the Height of the Rise (B1, B2).
Roof surface area
Total roof area (including overhangs of the specified length). Determines the amount of roofing and insulating materials that will be needed for the work.
Attic floor area
Total attic area ( living area attics). Does not include space under the side roof slopes.
Approximate weight of roofing material
Estimated total weight roofing material required to completely cover the roof area.
Number of rolls of overlapping insulation material
Total quantity insulating material in rolls, which will be required for roof insulation. The calculations are based on rolls 15 meters long and 1 meter wide. An overlap of 10% is taken into account.
Load on the side/ridge rafter system
Maximum load on the side/ridge rafter system. The calculations take into account the weight of the entire roofing system, the shape of the roof, as well as the wind and snow loads of the region you specify.
Side rafter length
Measured taking into account the overhang of the roof to the junction with the ridge rafter.
Ridge rafter length
Measured from the joint with the side rafter to the ridge of the roof.
Number of side and ridge rafters
The total number of side and ridge rafters required to construct a roof at a given pitch.
Minimum cross-section of side/ridge rafters, Weight and Volume of timber for rafters
The tables show the recommended dimensions of rafter sections (according to GOST 24454-80 Softwood lumber). The calculations take into account the roofing material, the area and shape of the roof structure, as well as the loads exerted on the roof. The adjacent columns display the total weight and volume of the rafters based on their use for the entire roof structure.
Number of side/ridge rows of sheathing
The total number of side and ridge rows of sheathing required for the roof being calculated.
Total number of rows of sheathing
The total number of rows of sheathing for the entire roof. To determine the number of rows of sheathing for half of the roof, just divide the resulting value by two.
Uniform distance between side/ridge sheathing boards
To evenly install the sheathing and avoid unnecessary waste of materials, you should use the value indicated here.
Number of sheathing boards standard length
To sheath the roof you will need the number of boards indicated here. For calculations, a standard 6-meter board length is used. The number of boards for the entire roof is indicated.
Volume of sheathing boards
The volume of boards in cubic meters will help you calculate the cost of sheathing. The total volume of sheathing for the entire roof is indicated.
Approximate weight of sheathing boards
Estimated total weight of all sheathing boards. The calculations use average values of density and moisture content for coniferous wood.
A gable roof is complex and large in area. building structure, requiring a professional approach to the design and execution of work. The largest costs go to building materials for rafters, sheathing, insulation, waterproofing, and roofing material. Our calculator gable roof will allow you to calculate the amount of material.
Using a calculator saves time when designing a roof, and your money. The final 2D drawing will guide you through the work, while the 3D rendering will give you an idea of what the roof will look like. Before entering data into the online calculator, you need to have an idea about the elements of the roof.
Rafter parameters
To calculate the rafter system of a gable roof, you need to take into account:
- roof load;
- step between rafters.
- type of roofing
- 100-150 mm with a span length of no more than 5 m, and with additional supports.;
- 150-200 mm with a span length of more than 5 m, with a step of more than 1 m, and if the angle is not large.
Important! Distance between rafters gable roof usually set to 1 m, but with a roof slope of more than 45 degrees, the pitch of the rafters can be increased to 1.4 m. For flat roofs, the pitch is 0.6-0.8 m.
The rafter legs are attached to the mauerlat, which runs along the perimeter of the house. For it, take either a board with parameters of 50x150 mm, or a beam of 150x150 mm (to distribute the load)
Sheathing parameters
For metal tiles, a sparse lathing is created with a board, the width of which is 100 mm, and the thickness is 30 mm. The board is packed in increments that must correspond to the longitudinal axis of the metal tile module - 35 cm (Super Monterrey).
For flexible tiles, the sheathing is made with big step, since OSB or plywood will be laid on top of it as a continuous carpet.
Important! When choosing materials, pay attention to moisture resistance and minimum thickness.
When installing warm roofs Between the waterproofing and the roof, a counter-lattice is made with a block, the thickness of which should be 30-50mm.
Roofing parameters
- To calculate the roof of a gable roof, you need to know the dimensions of the roofing material and the amount of overlap.
- Metal tiles for hard roofing are produced in a width of 118 mm (working 110), but the length can be different. The manufacturer can cut any length to order.
- Flexible tiles for soft roof has different sizes, so you need to look at specific material
- As for the choice of insulation, for Russia the recommended thickness is at least 100 mm, and the correct one would be 150-200 mm.
The main reason for the fairly widespread use sloping roof is that a conventional gable roof creates relatively little free space, which in most cases is not enough for use as a living space. At the same time, when erecting a sloping roof during the construction of a private house, it is possible to construct a full-fledged attic. At the same time, we should not forget that a sloping roof looks extremely attractive, giving residential building aesthetic and solid appearance.
Features of a sloping roof
The design of a sloping roof is a variation of the usual gable roof, with a small addition - there is a break on each slope. This essentially turns the roof into a hipped roof. The main purpose of such a change is to increase the under-roof space. Usually there is an attic, which is almost a full-fledged residential floor.
The construction of a sloping roof is somewhat more complicated than a regular gable roof, but is not very different from the construction of a hip roof. Basic design feature The roof in question is the presence of two types of rafters:
- Bottom (layered). In most cases they have a large angle, the value of which is equal to or greater than 60 degrees;
- Upper (hanging). The angle of their location is sharper, usually it does not differ much from 30 degrees.
Sloping roofs are most often used in private housing construction. Therefore, its width rarely exceeds 5-6 meters. This is explained by the much more complex design of the rafter system with a larger width, which complicates the work, increases its cost, making this design solution economically infeasible.
It should also be taken into account that the structure of a broken roof contains not only rafters, but some additional and auxiliary elements in the form of racks, struts, tie-downs, etc. Their dimensions are determined when calculating the rafter system. It is precisely because of their presence rafter system somewhat more complicated than that used with a gable structure.
We should not forget that an important advantage of a sloping roof is that it gives the appearance of the building a certain solidity, and simply looks much more attractive than a regular gable roof. It is precisely this combination of high functionality of the building, expressed in the possibility of equipping an attic, and extremely attractive and aesthetic appearance, largely explains the reason for the popularity of the design in question, despite its relative complexity.
Calculation of roof dimensions
The calculation of the size of a sloping roof can be conditionally divided into two parts.
Calculation of roof covering area
This part is the simplest and most uncomplicated. To calculate the area, simply make a plan of it with all the dimensions. In this case, the diagram will be a set of simple figures - in most cases quadrilaterals, in particularly complex ones constructive solutions- and triangles. Calculating the areas of these figures is not difficult, nor is adding them up to obtain the total coverage area.
But even these procedures can be performed using numerous calculators, which greatly facilitate the second part of the calculations.
Calculation of the dimensions of elements and parts of the rafter system
Calculating the dimensions of a rafter system for a sloping roof is much more difficult, including due to the fact that it contains many connecting rather complex units. But without them correct calculation and implementation is impossible for a long time and reliable operation roofs. The dimensions of the rafter system are influenced by many factors:
- weight components roofing pie:
- battens and counter-battens;
- completed waterproofing and vapor barrier;
- thermal insulation material;
- the direct weight of the roof covering;
- geometric dimensions of the main roof elements:
- the span from the eaves overhang to the roof ridge;
- the angle of the upper and lower rafters;
- selected pitch of sheathing and rafters;
- operational loads (weight of people repairing and maintaining the roof, engineering and maintenance devices, fences, aerators, skylights etc.)
Based on the list of factors listed above that influence the size of the required rafter system, it becomes clear that its calculation is not a simple operation. That is why a large number of auxiliary online calculators have been developed, with the help of which it is quite easy to perform all the calculations.
Calculators will do an excellent job of calculating the total area of the roof covering, as well as required quantity material for hydro- and vapor barrier.
To calculate the rafter system, you must enter the appropriate data into the calculator, which should characterize each of the above influencing factors.
The approximate wind load is easily determined from the corresponding map for each region.
The resulting wind load value must be adjusted depending on the coefficient, which takes into account the height of the building being constructed and the type of area where the construction site is located.
The amount of snow load that can affect the roof is taken from the corresponding map containing the relevant data for the regions of Russia.
Based on the area determined on the map, you can find out the amount of snow load required for calculation.
Most calculators independently calculate this parameter; it is enough to simply indicate the materials used and the main geometric dimensions of the designed roof, namely: the pitch of the rafters and sheathing, the angles of the slopes, the distance from the ridge to the overhang, as well as the material of the roof covering. The program will perform all other calculations offline.
After introducing all necessary information, the calculator will give all the necessary dimensions of the elements and parts of the rafter system, as well as the roofing area and the necessary vapor and waterproofing materials.
Use the online mansard roof calculator to calculate the required amount of materials for this type of roof. Accurate calculation of the sheathing, the angle of inclination of the rafter system, and the load on the roof of the house.
Specify roofing material:
Select a material from the list -- Slate (corrugated asbestos cement sheets): Medium profile (11 kg/m2) Slate (corrugated asbestos cement sheets): Reinforced profile (13 kg/m2) Corrugated cellulose-bitumen sheets (6 kg/m2) Bitumen (soft , flexible) tiles (15 kg/m2) Galvanized sheet metal (6.5 kg/m2) Sheet steel (8 kg/m2) Ceramic tiles (50 kg/m2) Cement-sand tiles (70 kg/m2) Metal tiles, corrugated sheets (5 kg/m2) Keramoplast (5.5 kg/m2) Seam roofing (6 kg/m2) Polymer-sand tiles (25 kg/m2) Ondulin (Euro slate) (4 kg/m2) Composite tiles (7 kg/m2) ) Natural slate (40 kg/m2) Specify the weight of 1 square meter of coating (? kg/m2)
kg/m2
Enter roof parameters:
Laying width A1 (cm)
Laying width A2 (cm)
Base length D (cm)
Lifting height B1 (cm)
Lifting height B2 (cm)
Length of side overhangs C (cm)
Front and rear overhang length E (cm)
Rafters:
Rafter pitch (cm)
Type of wood for rafters (cm)
Working area of the side rafter (optional) (cm)
Lathing calculation:
Sheathing board width (cm)
Sheathing board thickness (cm)
Distance between sheathing boards
(cm)
Snow load calculation:
Select your region using the map below
1 (80/56 kg/m2) 2 (120/84 kg/m2) 3 (180/126 kg/m2) 4 (240/168 kg/m2) 5 (320/224 kg/m2) 6 (400/280 kg/m2) 7 (480/336 kg/m2) 8 (560/392 kg/m2)
Wind load calculation:
Ia I II III IV V VI VII
Height to the ridge of the building
5 m from 5 m to 10 m from 10 m
Terrain type
Open area Closed area Urban areas
Calculation results
Angle of inclination of side rafters: 0 degrees.
Angle of inclination of ridge rafters: 0 degrees.
The angle of inclination is suitable for this material.
It is advisable to increase the angle of inclination for this material!
It is advisable to reduce the angle of inclination for this material!
Roof surface area: 0 m2.
Square attic floor: 0 m2.
Approximate weight of roofing material: 0 kg.
Number of rolls of insulating material with 10% overlap (1×15 m): 0 rolls.
Rafters:
Load on the side rafter system: 0 kg/m2.
Load on the ridge rafter system: 0 kg/m2.
Side rafter length: 0 cm
Ridge rafter length: 0 cm
Number of side rafters: 0 pcs.
Reduce the pitch of the rafters!
Number of ridge rafters: 0 pcs.
Reduce the pitch of the rafters!
Lathing:
Number of side rows of sheathing (for the entire roof): 0 rows.
Number of ridge rows of sheathing (for the entire roof): 0 rows.
Total number of rows of sheathing: 0 rows.
Uniform distance between the side sheathing boards: 0 cm
Uniform distance between the ridge boards of the sheathing: 0 cm
Number of sheathing boards with a standard length of 6 meters: 0 pcs.
Volume of sheathing boards: 0 m3.
Approximate weight of sheathing boards: 0 kg.
About the calculator
The online attic roof calculator will help you calculate the angles of inclination of the side and ridge slopes, the number and required cross-section of rafters, the volume of sheathing and other materials for roof construction. You won't have to do extra calculations because this calculator includes most existing roofing materials, such as bitumen shingles, cement-sand and ceramic tiles, metal tiles, bitumen and asbestos-cement slate, ondulin. If you use non-standard material, or want to get more accurate calculations, you can specify the weight of your own roofing material by selecting the appropriate item in the drop-down list of materials.
Before designing an attic floor, read SNiP 2.08.01-89 “RESIDENTIAL BUILDINGS” seriously.
Pay attention!
The calculator makes calculations in accordance with the current SNiP “Loads and Impacts” and TKP 45-5.05-146-2009.
The design of a mansard (broken, sloping) roof is different in that on each side it contains two slopes with different angles of inclination: a steep side slope and a sloping hanging one. Thus, under the roof a comfortable space, which can be used as a living space. This room is called the attic floor or simply the attic.
Attics were first built in the 17th century. An attic can be erected relatively easily, both during the initial construction of a building and as an addition to an existing building. Thus, it provides an alternative in the construction of an additional floor.
Since the side slopes are very steep, you should carefully choose building materials. Perhaps an attic roof will require additional costs. This is especially important for residential attic spaces: they will need larger gable windows and improved thermal insulation.
When filling out the fields of the calculator, read the additional information located under the sign.
If you have any questions or ideas regarding this calculator, you can write to us using the comment form at the bottom of the page. We'd love to hear your opinion.
Additional information about the calculation results
Angle of inclination of side rafters
The angle at which the side rafters are inclined to the plane of the ceiling. He's usually cooler. Different roofing materials allow different maximum angles. The calculator will show whether it is possible to build a roof at a given angle using the selected roofing material.
Angle of inclination of ridge rafters
The angle at which the ridge (hanging) rafters are inclined to the plane of the attic floor. This angle is usually more sloping. Different roofing materials allow different maximum angles. The calculator will show whether it is possible to build a roof at a specified angle using the selected roofing material.
Roof surface area
The area of the entire roof surface including overhangs. To determine the area of one slope, it is enough to divide the indicated value by two.
Attic floor area
The area of the attic premises. This does not include the area under the side slopes.
Approximate weight of roofing material
The weight of the selected roofing material for the entire roof area, taking into account overhangs.
Number of rolls of insulating material
The required amount of insulation material for the entire roof area. The quantity indicated in rolls is based on standard size roll - 15 meters long, 1 meter wide. The calculation also took into account an overlap of 10% at the joints.
Loads on the side and ridge rafter system
These values show the maximum possible loads on a given roof. Participates in the calculations as total mass roofing pie, and the sum of wind and snow loads of the selected region.
Side rafter length
The estimated length of the rafters of the side slopes, located from the bottom of the slope to the top of the attic floor.
Ridge rafter length
The estimated length of the ridge (hanging) rafters, located from the top of the attic floor to the roof ridge.
Number of side and ridge rafters
The total number of side and ridge rafters required to construct a roof with the given parameters.
Minimum section of rafters / Weight of rafters / Volume of beams
- The first column indicates the permissible cross-sections of rafters in accordance with GOST 24454-80 Softwood lumber. Weight is taken into account given parameters structures, possible roof loads. The calculator calculates the total loads that can affect the structure and selects optimal options rafter sections.
- The second column contains information about the weight of rafters with the specified cross-section. The total weight of the rafters for the calculated roof is indicated here.
- The third column displays the total volume of rafters in cubic meters. Use these values to calculate the cost of lumber.
Number of rows of sheathing
The number of rows of sheathing that will be needed for the entire roof with the given parameters.
Uniform distance between sheathing boards
Number, volume and weight of sheathing boards
The total number of boards for arranging the roof sheathing, their volume in cubic meters and their total weight.
There are two types of attic structures: with a sloping roof, as a rule, these are alterations of non-residential attic spaces and with a sloping roof, which is provided for by the design of the house and was designed from the beginning. The use of the second type is preferable, as it provides more usable space. However, the design and calculation of a sloping type mansard roof is much more complicated. This article will show you how to use special online calculators to obtain the basic parameters of a mansard roof: the number and cross-section of the main load-bearing elements, the angle of inclination of the side and hanging slopes, the type of roofing material, as well as the approximate cost and quantity of building materials.
What you need to know to make calculations
On the Internet you can find many online calculators with which you can calculate the attic roof. They can be specialized - for calculating the cross-section of the main load-bearing elements, usable area premises, the angle of inclination of the slopes or the distribution of the load on the rafter legs or universal ones. Use the second type of online calculators for non-specialists in construction industry quite difficult, since these programs will require much more initial data for calculation and operate with such specific terms as Mauerlat, struts, rafters, etc.
Let us highlight the main structural elements, the dimensions and quantities of which should be given by the attic roof calculator:
Rafter legs
The main load-bearing element of the roof structure. For residential buildings, most often, round or round beams are used as the material for making rafters. square section. Is it allowed to be used? both solid wood and laminated timber. There are two types of rafters:
Layered(from the word lean) the lower ends are installed on the wall of the building, in the middle part they rest on intermediate supports. They are used in sloping roof structures, if the span width between load-bearing base exceeds 4.5 m;
Hanging– are used if the structure does not have internal load-bearing elements: columns, walls, beams on which additional supports can be located. The maximum span width is 6.5 m. Hanging rafters form sloping roofs and are not very convenient for creating attic floors.
Racks
Additional load-bearing elements(pillars) giving the roof structure additional strength. In the attics small area with a simplified design, they rest on the floor slabs and directly support the rafters. In more complex structures for mansard roofs, the racks rest on the beams and act as a load-bearing base for the purlins;
Mauerlat
One of the most important elements rafter system. Designed for transition from concrete or brick wall To wooden structures. Simply put, this is a beam with a cross-section from 150x100 mm to 200x200 mm, which is laid on load-bearing wall along it and is the main support for rafter legs. The materials used for production are conifers wood Special attention it is necessary to pay attention to the issues of protecting the element from moisture and mold, as well as waterproofing between the wall and the Mauerlat.
Lezhny
In fact, this is the same Mauerlat, but located not on the wall, but on attic floor. Its main purpose is to distribute the load from the racks over a larger area. That is, the racks will not put pressure on the attic floor at one point measuring 150x150 mm (which can cause damage to the floor). The bench distributes the pressure from the racks over a large area, similar to how skis distribute the weight of a person, and he does not fall into the snow.
Run
A load-bearing element designed to support rafters. It is used if the roof slope is long and/or the roofing material has significant weight.
On our website you can get acquainted with the most . In the filters you can set the desired direction, the presence of gas, water, electricity and other communications.
Calculation of various elements of the attic roof
You can calculate the area of the attic roof using two types of calculators. The first is an application written in a calculation program, the most popular is Microsoft Excel. This type The calculator is quite complicated, as it requires not only knowledge in the construction industry, but also some experience in using Excel. However, it can be used to make fairly accurate calculations.
The second type of applications are small online calculators posted on the websites of companies involved in construction or the sale of building and roofing materials. The accuracy of such calculations is relative, but they can guide the buyer on the approximate amount he needs to expect when building an attic.
Dependence of the steepness of the lower slope on the height of the room
The calculator calculates the angle of inclination of the lower attic rafters at a certain width of the house and planned ceiling height. In order to calculate the attic roof, the following data is required:
Size walls under the pediment - Vd;
Height premises – Nm;
Width premises - Vm;
Width“dead” area of the attic - Vg;
Height skate - Nk.
The calculation is carried out using a simple geometric formula Вг=Нв/tg α. As a rule, such applications specifically limit the possibility of entering incorrect data.
The calculator makes it possible to calculate several quantities at once: the offset of the floor beams and the angle of inclination of the attic rafters. The calculation can be made either by entering the height of the room and the angle of inclination of the side rafters, or in the reverse order. By indicating the required dimensions of the room, you can obtain the angle of inclination - α, of the side (lower) rafters.
Calculation of the height and angle of inclination of ridge slopes
This calculation of a sloping roof is necessary to obtain the total height of the house. It is necessary to take into account that the angle of inclination of the rafters of the ridge slope, as a rule, is taken within the range of 15°-30°.
The calculation formula will be as follows: Нк=Вм×tg β
The calculator will ask you to specify the width attic room and the planned angle of inclination of the ridge rafters. Also possible solution inverse problem, indicated the total height of the entire building and the planned height of the ceiling of the attic floor, the program will calculate the angles of inclination of the ridge and side rafters.
Calculation of the length of the rafter leg
Regardless of whether the rafter is part of the lower or ridge cattle, the calculation formula is the same in both cases: L=H/sinα(β), where
L– length of the rafter leg;
N– either the height of the attic space Nm, or the height of the ridge segment Hk.
α/β – the corresponding angles of inclination of the stops.
Calculation of loads on the roof structure and determination of the optimal cross-section of rafter legs
The main load on the load-bearing elements of the roof comes from the roofing material, as well as snow and wind loads. At the same time, a safety margin is laid down in the event of a natural disaster, for example, a hurricane wind that is atypical for the area. When selecting a section, they operate with the concept of distributed load. This value depends on the number of rafters, respectively, on the step of their installation - the smaller it is (the more rafter legs are used), the smaller the cross-section of each element will be.
The calculator for calculating the rafter system of an attic roof is more complex and will require information not only about the angle of inclination of the roof slopes, but also about the location of the structure on the ground, and about the region of construction in order to determine the level of snow and wind load.
Roofing type
At the moment, the most popular roofing materials for the construction of an attic floor are:
Metal tiles– characterized by high strength, resistance to mechanical damage, fading, and temperature changes. Provides a wide selection of reliefs and a rich color palette;
Roofing corrugated sheets– the main performance indicators are similar to metal tiles, however, the decorative possibilities are very limited. The building is mainly used as a roof for industrial and technical purposes;
Pulp-bitumen sheets (ondulin) - has a limited service life (15-20 years), fades in the sun, and becomes brittle under the influence of frost. IN in good condition also exhibits rather low mechanical strength;
Ceramic tiles– has high aesthetic and performance indicators, however, the large weight of the roofing material necessitates the use of a reinforced rafter structure.
Video description
In the video you can see the calculation of the attic roof:
Snow and wind loads
Snow and wind load zones are determined using special maps. Depending on the zone in which the house is located, certain coefficients are substituted into the attic formula when calculating.
Calculation of insulation thickness
The thickness is calculated in the same way thermal insulation material for the attic. Using a special map, the thermal resistance coefficient in the construction region is selected - this value is supplied to the program, after which the type of thermal insulation material, as well as the material for interior decoration indicating the thickness of the skin.
Calculation of roofing area
Calculating the roof area is an elementary task, for which universal calculators do not even have a separate function. As a rule, roofing calculators are used exclusively by websites selling roofing materials. The calculation is carried out using the following formula: S=2×D×(Lm+Lk), where
S– total roof area. When purchasing roofing material, it is necessary to take into account the specifics of its installation. In fact, for each type of roofing there is a coefficient or percentage by which you need to increase the amount of roofing material when purchasing.
D– Roof length along the eaves or ridge line;
Lm– Length of the rafters of the lower overhang of the attic;
Lk Ridge rafter length.
Video description
In you can see the design diagram of the attic:
Conclusion
It is important to consider that the area, cross-section and type of sheathing are selected individually for each roofing material.
It is even more important to understand that the data provided online calculators of any type are imprecise, they are suitable only so that the home owner can navigate the choice construction company contractor.
