Supporting the aquarium

This guide is for individuals who are comfortable with building construction and have experience with either concrete or wood frame construction.  The information in this guide is not intended to be a recommendation for your specific situation.  The material presented here is educational and intended to motivate the reader to seek professional advice before placing an aquarium in their dwelling.

Small aquariums of 30-50 gallons are common and require little structural planning before their purchase and placement.  However, larger aquariums above 50 gallons do require some forethought before their placement.

The placement of an aquarium that is in excess of 50 gallons requires that the aquarist consult an architect or structural engineer to perform a dead load analysis of the floor construction where the aquarium will be located.  The reasons for this are that most dwellings are not constructed with sufficient floor support to accommodate weight in excess of 500 lbs (50 gal tank).  A 50 gallon tank is roughly the same weight as an upright piano or baby grand piano.

Most dwellings in the United States average between 10-20 Lbs/square foot dead load capacity.  Consider a 70 gallon tank placed in a wood constructed home.  A 70 gallon tank weighs in at approximately 700 Lbs, it occupies an average 8 sq ft of floor space, requiring a floor to support 87 Lbs/sq ft.

Considering that the floor is at most designed to carry 20 lbs/square ft of dead weight, the tank is 300% over the rated capacity of the floor.  That weight is well above the rated dead load specification to which a home is constructed.  This is why it’s so important to check with a structural engineer to determine if the floor joist architecture is able to support the extra weight.

Each country, and occasionally states within countries, have standards to which dwellings are constructed.  In the United States  building codes are established by states and counties, in Columbia the standard is known as the “Reglamento Colombiano de Construcción Sismo Resistente” (Colombian Seismic Resistant Construction Code), often referred to as NSR-10, adopted in 2010.  In South Africa the building code is called the National Building Regulations and Building Standards Act, which was enacted in 1977.

Without regard to location, there is typically a specification to which buildings must adhere in their construction.  The focus in this guide is with a small fraction of the specifications having to do with weight bearing construction as it pertains to dead load weight bearing.

Dead load and live load are terms used in structural engineering to describe different types of loads that a structure or building must support. Understanding the distinction between these two types of loads is essential for designing safe and structurally sound constructions.

Dead Load: Dead load refers to the weight of the permanent and stationary components of a structure. These components include the building’s own weight, as well as the weight of fixed elements such as walls, floors, roofs, beams, columns, and other permanent fixtures. Dead load is relatively constant and does not change unless modifications are made to the structure itself. It is considered a static load because it is always present and acts downward due to gravity.

Examples of dead load include the weight of the building materials themselves (concrete, steel, wood, etc.), as well as the weight of non-structural elements like drywall, insulation, fixed equipment, and unusually heavy items like aquariums, weight machines, and safes. Engineers take dead load into account when designing a structure’s foundation, beams, and columns to ensure they can safely support these permanent, and semi-permanent loads over time.

Live Load: Live load, on the other hand, refers to the variable and transient loads imposed on a structure due to the people, furniture, equipment, and other moveable objects that occupy the space. Live loads can change over time and are not constant. They are considered dynamic loads because they can fluctuate and move around within a structure.

Examples of live load include the weight of people walking, furniture being placed, equipment being operated, and even snow or wind loads in certain situations. Live loads can be significantly different from one location to another within a building, and they influence the design of floors, walls, and other structural components to ensure they can support these varying loads safely.

Design Considerations: When designing structures, engineers consider both dead load and live load to ensure that the construction is strong enough to support both types of loads without exceeding safety margins. A structure’s capacity to handle live loads is often determined by its ability to accommodate peak load conditions without significant deflection or failure.

Dead load represents the permanent weight of the structure and its fixtures, while live load accounts for variable and transient loads due to occupants, furniture, and equipment. Properly accounting for both dead and live loads is essential in engineering to ensure the safety and integrity of buildings and structures over their intended lifespan.

The size, placement, and underlying construction of the dwelling are each critical and are thoroughly intertwined with one another.

The size of the aquarium will determine the amount of water to be held.  The amount of water will  affect the total weight of the aquarium.  The total weight of the aquarium and related equipment will determine the affect the aquarium will have on the dwelling itself.

Often the location of an aquarium is an emotional decision of what will look good or be convenient.  This decision can be very emotional and easily accommodated during the construction phase of the dwelling when accommodations can be made to the physical building addressing the increased loading of the aquarium.

Once construction is complete and walls closed in the decision of where to locate an aquarium needs to be one of practicality and structural research.  A new owner of a property can’t guess how a dwelling is built, but must research the building.

Researching the building may require the services of a structural engineer or architectural firm.  These people are certified in their fields and well able to provide expert advice.  Conversely, most counties require the builder to submit construction plans detailing a structure’s live and dead weight load specifications, and the physical placement of beams, joists,and columns.  Providing a copy of these plans will assist the architect or structural engineer in providing expert advice on aquarium placement.

If your building has concrete floors, the advice from a structural engineer or architect is less important.  This is due to the amount of weight a concrete floor can support.  Still, if your aquarium will exceed 100 gallons, it is still a good idea to pass the location by an architect.

If you are going to be placing your aquarium on a concrete floor, the size of the aquarium and associated water volume are less of a concern.  This is due to concrete’s ability to withstand significantly greater weight before structural failure.

Even though concrete has greater load carrying capabilities, it is still important to consult an architect and/or structural engineer to confirm the existing dead load specification and the proposed location of the aquarium.

In a multi family dwelling with neighbors below, it is important to know if the neighbors below are placing any load on the ceiling of their unit (floor of your unit).  The structural engineer/architect will want to know where the proposed aquarium will be situated, the distance from support columns, the thickness of the floor, and the type of reinforcement used in construction.  All of these elements will assist in determining placement of the aquarium.

Depending on your occupancy agreement (in a multi family dwelling) the building owner may require the involvement of a structural engineer/architect.

Placement of an aquarium containing 100+ gallons of water is a delicate task.  The floor must be absolutely level with no protrusions of any kind.

Surprisingly, it is uncommon to find a concrete floor that is level without any deformations in the concrete surface.  Most construction has some deformation, usually near the vertical posts.  The farther from the vertical posts the greater the possibility of finding a floor without deformations.

Because deformations are so common the aquarist must be prepared to engineer a level floor under the aquarium base that will provide a 3,000 psi compression strength before structural failure.  As it turns out, the best person to level a floor is a bathroom installer.  These folks are experts in leveling floors for tile.  They are used to floor deformities and they have great experience in creating large level surfaces with cement.

Additionally, tile contractors can place high density tile on the leveled floor to support the aquarium base.

The reason for wanting a level surface is because of the aquarium frame.  The frame of the aquarium sits directly on the floor and must be in constant contact with the floor to properly distribute the water weight of the aquarium.  An uneven floor will cause the frame to unequally distribute weight and may result in frame failure.

Wood frame construction is a very common type of construction in many homes.  The advantages of wood are cost and versatility.  Wood gives the builder a medium that is easily shaped and fastened.  Because of its’ versatility there are a number of different methods used to construct homes and businesses.

Platform Framing: Platform framing, also known as stick framing, is the most common type of wood frame construction. It involves constructing individual wall sections (platforms) on the ground and then raising and connecting them to create a building’s frame. This method is used for both residential and commercial buildings.

Balloon Framing: Balloon framing was commonly used in the past but is less common today. It involves long vertical studs that extend from the foundation to the roofline, creating a continuous framing structure. While efficient in terms of materials, it can pose fire hazards due to open cavities.ood candidate for large aquariums.

This method also has weight bearing problems with mid floor attachment to the long vertical studs.  The attachment point is typically nailed or screwed into the vertical stud and relies upon sheer strength to keep the floor in place under load.

Timber Frame Construction: Timber frame construction uses larger wooden beams and posts that are often joined with mortise and tenon or other traditional joinery methods. This type of construction is known for its aesthetic appeal and is used for creating open, spacious interiors in residential and commercial buildings.

Depending on the joist arrangement, this type of construction is very strong and able to support significant weight loads.

Post and Beam Construction: Post and beam construction utilizes vertical posts and horizontal beams to support the structure. This method allows for larger spans and is often used for creating rustic or traditional designs.

This construction method is similar to timber frame construction in its ability to support impressive weight loads.

Platform-and-Balloon Hybrid Framing: This hybrid method combines elements of both platform and balloon framing. It uses platform framing for the first floor and balloon framing for the upper floors. This approach reduces the height of vertical studs while maintaining structural integrity.

Modern Methods (Panelized and Modular): In modern wood frame construction, panelized and modular techniques are used. Panelized construction involves pre-fabricating wall panels off-site and then assembling them on-site. Modular construction involves constructing entire sections of a building off-site and then transporting and connecting them to create the final structure.

This method can be designed to support impressive weight loads by using larger studs (2×6) and taller joists (2×10 or 2×12).

Advanced Framing (Optimum Value Engineering – OVE): Advanced framing techniques aim to reduce material waste and increase energy efficiency. Techniques include using fewer studs, increasing spacing between studs, and optimizing the layout to minimize thermal bridging.

This method of construction is not designed for large weight-bearing areas.  With reduced stud counts and unpredictable horizontal placement, the weight bearing capability of the building is always an unknown, and not easily upgraded to accommodate significant changes in weight loading.

Pods and Pods-Plus: Pods are factory-built room units that can be pre-finished and outfitted with fixtures, then installed on-site. Pods-Plus takes this concept further, integrating building systems and services within the factory-built units.

This method has too many unknowns to be a good candidate for large aquariums.

The base for the aquarium will need to rest on a flat tiled floor.  Employ a bathroom remodeler to accomplish this part of the aquarium preparation process.  The architect will most likely specify an additional course of 1″ pressure treated plywood on top of, or replacing existing subflooring.  On top of the plywood the architect may have a 2-3 inch poured cement and wire base installed to further enhance the weight distribution of the aquarium in the building framing.

The tile contractor will finish the floor with a high compression floor tile able to withstand the weight from the aquarium frame.

When placing a 100+ gallon aquarium on a wood frame building the aquarist needs to think “bottom up”.  Starting with the basement of the dwelling one needs to determine if there is sufficient wood framing to support the next floor.  Thus is how it got it’s name “bottom up”.

With a timber frame or post and beam construction style, there should be plenty of support for significant weight loads.  However, always involve an architect/structural engineer to determine the weight bearing limits of the existing construction.

Keep in mind that wood framed buildings are designed to move as the weather changes.  When humidity rises the wood building swells, and when humidity lowers the building contracts.  This constant motion under significant load weight can cause deflection in support joists.  For this reason the architect may suggest increasing the number of joists, add blocking between the joists, and/or adding a beam to reduce the deflection of the joists.

If you are using pressure treated lumber to make structural changes to support additional load weights, be sure to let the lumber acclimate and dry out prior to use.  Most pressure treated lumber comes wet from the lumber yard.  As the lumber dries it will shrink in size, particularly in the length dimension of the lumber.

Cutting to dimension and installing pressure treated wet lumber will always result in unlevel finished work.  Give lumber a few weeks to dry before use.

PARTICLE BOARD

Never purchase an aquarium stand that contains particle board.  Moisture causes it to disintegrate.

 

CHIP BOARD

Never use a stand made from chip board.  Water in unequally absorbed by the wood chips and causes weakening of the board.

 

Never use MDF

MDF is a manufactured board that is prone to breakdown once it becomes damp.

 

FORMICA

Do not use formica counter-tops as a substrate upon which an aquarium is placed.  Formicaa is almost always placed on manufactured wood that deforms when wet.

 

Steer clear of soft woods

When building an aquarium frame steer clear of using softwoods in the construction.  Softwoods are more sensitive to expansion and contraction from humidity.  The joints need to be engineered using compression style joining.  This means no sheering mechanical connections between boards.  Always have at least 50% of the structural member supporting the next structural member vertically through resting one on another.  This reduces dependency on sheer strength of connecting hardware and the inevitable loosening of the same.

 

NO GAPS

When supporting an aquarium steel frame there should be no gaps between the steel frame and the floor on which the frame rests.