Wall sections form a key component of the design and construction process, by providing a vital form of communication for both architects and contractors.
However particularly for architecture students and young/inexperienced licenced architects, when it comes to producing such a drawing, they can be incredibly intimidating.
In this article, we will be discussing the fundamental purpose of a wall section, and the important considerations and aspects that go into producing a successful drawing and detail.
Defining wall section drawings
In short, a wall section is a technical drawing that shows the internal parts and inner workings of a vertical wall for construction purposes. Both external and internal walls can be incredibly complex and made up of all manners of materials and construction techniques, as result there is rarely a one size fits all, and so hence why their communication is so important.
The purpose of detail drawings
Detail drawings provide a geometric outlay of a single component. In construction, this could be a commercial, private, and/or public building or structure. There are several purposes of detailed drawings. One of them is to depict compliance with the standards and codes of the area where the construction is to be situated.
These compliance factors might include building regulations and laws, standard practices, requirements within certain frameworks, construction details, detailed form, and many more. All of these are done because it would be nearly impossible to put these complex details onto a general arrangement drawing.
Detail drawings allow for clarity in passing information. This also gives an increased sense of awareness to know important information such as dimensions, specification information, and other key pieces involved in the construction process. It is very important to point out that detail drawings should not be confused with “detail design drawings” and/or “working drawings.”
Proper detail design drawings are achieved when the design is developed in a way that is coordinated and correct in its dimension. This couples all the elements of the building and how they all function together. For working drawings, we have the dimensional and graphical information of the building. This is usually used by the contractor or anyone involved directly with the construction to implement their work. It is therefore important to point out that not all design and working drawings will be needed for detail drawing.
Things to consider for wall section detail
Bearing vs non-bearing wall sections
Depending on the type of construction being carried out, there are two types of walls namely structural and non-structural. Structural walls as the name suggests are responsible for carrying the weight and load of the building, and are therefore a lot more substantial in size.
Non-structural walls are typically found internally and generally serve as room dividers. They do not support the weight of the building and are therefore much lighter, and thinner, consideration has to be given in choosing between these two types based on their functions.
R-values and sound attenuation
R-value is an important aspect to consider when designing a wall’s make-up. An R-value reveals the insulation of a wall section and measures the heat resistant levels in several materials. This is particularly important for cold and mid temperature environments.
Thicker walls will guarantee a combination of materials thereby ensuring a higher R-value, helping to ensure that heat does not escape easily. Several materials work well as insulators. Some of them include fiberglass which does not absorb water, mineral wool which does not melt or support combustion, cellulose, and polyurethane.
Cladding simply means the application of one material over another to serve as a layer. Not only does it serve as an aesthetic, but it also functions as insulation and weather resistance. The material behind the cladding is the waterproof membrane that does not allow the structure to become affected.
The moisture acts as a nemesis to timber cladding so it is necessary to take adequate steps to prevent moisture from destruction. This is why waterproof membrane, damp-proof course (DPC), and flashing which are materials installed to stop water passing into a structure are all necessary to consider. Movement and shrinkage should be looked into when detailing timber cladding.
There are several options available when designing timber cladding. Horizontal cladding is very common and simple to achieve. Boards are nailed to a base material, usually a strip of solid material or wood in a vertical manner. Vertical timber cladding function when counter battens enable moisture to run off in a hole. The most common is the board on board which tolerates the movement of timber. For diagonal timber cladding, the boards are angled at a 45-degree position and are affixed to a strip of solid material or wood, while allowing moisture to run off.
Types of roof
The roof is one of the most important structures in a building because of the function it serves. Depending on building regulations in your area, some stipulations and guidelines cover its functional requirements. When a roof has a slope of 1-5o to the level, it is thought to be flat. Flat roofs are inexpensive, unlike pitched roofs. However, they have a shorter life span.
Some of the functional requirements include fire safety and security, aesthetics, insulating the passage of sound, thermal insulation, and many more. Generally, roofs are flat or slanted and timber is mostly used as material for roofs.
Cold Roof – For a cold roof to be achievable, insulation is directly positioned above or between the ceiling structure. The cold roof system needs ventilation to prevent a build-up of moisture concentration in the spaces between the roof. The pipes carrying water have to be insulated to stop damage from freezing, as the roof space itself is a cold unheated space. This type of roof is challenging as it is hard to provide appropriate airing between the spaces above the insulation that stops condensations. It also leads to wasteful cutting of insulation between the rafters.
Warm Roof – When the roof serves as part of a building or as storage, a warm roof is used. Warm roof systems profit from insulation sitting just above the deck or between the beams. A warm roof’s benefit is that it is warmed by heat which comes from rooms below it. Unlike a cold roof, there is less chance of condensation happening, so there is usually no need for ventilation. However, there are usually fluctuations in temperature with the way it is set up.
Inverted Roof – An inverted roof is a flat roof where the layer that provides waterproofing is under the thermal insulation, as opposed to being above it. Insulation is therefore put above the roof covering to achieve an inverted roof. Concrete paving and layers of chippings then protect the insulation as often seen in commercial constructions. It is highly advantageous because it stops wasteful cutting and decreases installation time, which in turn leads to a cheaper installation cost.
Pitched Roof – A pitched roof slopes downwards in two parts at an angle from a central point, and at other times from one edge to the other. Pitched roofs are built in an even manner and equal slants meet at a central point. Usually, sheets, bituminous felt, or plastic sheeting form a secondary weatherproof structure under the roof tiles. The loft of a pitched roof is protected from the rain because of its construction method which extends between 150-300mm beyond the external surface of the wall.
Connecting Windows and wall sections
Cavity closers are usually advised for use when designing openings in brickwork. A damp-proof course (DPC) used with insulation can also be employed to side-step cold from entering through the opening. DPCs backed with insulation in window frames are positioned to form a barrier that prevents rain coming in between the window frame and its column. Furthermore, the sill functions as protection from a wall below a window.
Their shape is therefore in a slope that lets water run off of it. A lintel supports the blockwork at the head of a wall’s opening. An effective lintel arrangement helps limit cold. However, steel section lintels are mostly used as they act as a damp-proof tray.
Concrete or timber is the most commonly used material for floors. Whether it be the ground or upper floor, there is a need for different variables to be put into consideration. The longevity and strength, sound resistance, fire resistance among other factors are looked into to pick out materials to use during construction. In this case, there are different types of floors according to the structure being proposed.
Ground bearing and suspended concrete floors – Ground bearing floors and suspended concrete floors are two types of concrete floor systems commonly used in construction. For ground bearing floors, the ground below supports the concrete slab. However, suspended concrete floors do not need support and are braced by the foundations below and external walls. Pre-cast concrete planks or slabs are used to construct this with the help of block systems.
Beam and block floor – Beam and block floor systems use concrete T beams that run between walls and concrete-filled blocks. These are then placed in-between the beams to act as a dense base for the leveled layer of material. Depending on the load it will support, the depth of the joists is usually between 130mm and 250mm. Make sure to shield the floor with a water-resistant barrier. This will help stop wetness from entering the building from the ground.
Damp Proof Course (DPC)
DPC is a blockade through the structure created to stop wetness from a passageway. Usually made from a thick polyethylene, it is laid under a concrete slab to help to stop wetness gain. Conventionally, the DPC is placed in isolated external and internal strips, 150mm minimum above the external ground level.
The main purpose of foundations is to provide support for any structure. In doing so, the load of the building rests on surrounding soil. Regulations must be followed depending on location to ensure strict adherence in its construction. The foundation must also act as protection for the timber frame structure.
Foundation types – We have four types of foundations and they are strip foundation, pile foundation, raft foundation, and pad foundation.
Strip foundations are very common and they are made up of reinforced concrete under a load-bearing wall. Strip foundation is cost-effective and its channel is a deeper fill bringing it closer to ground level.
Pile foundations are used if trees are near structures. Long concrete structures are drilled into the ground to support the soil underneath. When ground conditions are poor, a raft foundation is used. It spreads the load over the whole ground.
Lastly, the pad foundation supports ground beams where a structural wall is constructed. Pits are dug to an acceptable depth, and the concrete is cast afterward. Bricks are then built on concrete joists that support the walls.
Drawing a wall section detail
A wall section is one of the primary tools used to communicate a building’s structure. We mentioned that wall sections describe in detail what the foundations, wall, floor, and roof are made of. Therefore, some of the issues we have touched on must be looked into.
For example, what kind of foundation is the structure going to require. What is the structure itself going to be e.g. a two-story building or a skyscraper? Insulation also needs to be considered as well as its location.
Window and door heights and roof pitch and materials. All these notes come together to help in drawing an effective wall section.
Tips for drawing wall section detail
A typical wall detail saves time, helps builders have easier access to information, and creates a better construction outcome
- Use notes and pointers to hit your mark
- Use graphics to describe your notes
- Start a fresh sheet when a wall is different
- Tag your walls using designated symbols and letterings
The most important aspect of wall sections is following building regulations and codes. We deduced that plans can be altered but the technical recommendations have to be followed to avoid disaster. Depending on the structure to be constructed, we must put into consideration the foundation and floor type, wall type, roof type, wall section, and other factors in achieving sustainable yet aesthetically pleasing construction.