Suspended Timber Floors

Things to considered when constructing or renovating a timber floor.

It is possible to create a suspended floor of any size using sleeper walls to bridge the span. The span that can be achieved is determined by the size of the timber joist used.
Using timber joists means that they are going to be susceptible to damp and rot if not laid properly. The joist ends for new flooring joists should be laid on galvanised joist hangers, rather than embedded in walls.
Where the joist rests on a wall such as a sleeper wall there must be a damp proof course between the wall and the timber.

Ventilation beneath a hollow timber floor is needed as if any moisture that collects cannot be ventilated away can cause rot. Airbricks need to be fitted on external walls and ventilation through the sleeper walls is required, whether using airbricks or half brick gaps in the wall construction

There is many systems out there, but the best is the “DANSKIN” system. This will level out any floor

Noo they shoud do proper job with proper timber

Hollow floors, also known as suspended or timber floors, are simply timber joists suspended across and supported by load bearing walls under the floor. The ends of these timber joists are built into, or suspended by joist hangers from the external walls of the property.

There are suspended concrete floors but we do not cover these here as they are more typically used in new build projects as they tend not to be economical under around 50m2. Here we are going to focus on floating timber floors (all these terms are interchangeable).

This doesn’t seem right. I’d prefer to look at this before giving an opinion

The method your contractor used for installing the suspended timber floors, particularly the use of cut pieces of ply boards, tongue and groove floorboards, packers as a base, and an 8mm adjustable decking pad to support 50mm timbers, is not a standard approach for high-quality flooring installations. Typically, a more robust and precise method is preferred, especially in professional settings, to ensure stability, durability, and levelness of the floor. Here are a few considerations:

Structural Integrity and Load Distribution: The primary concern with the described method is whether it provides adequate structural integrity and evenly distributes the load across the floor. The use of packers and cut pieces may not offer the best support and could lead to uneven floor levels or more serious structural issues over time.
Moisture and Ventilation: Suspended timber floors require careful consideration of moisture control and ventilation to prevent rot or deterioration of the timber. The construction method should ensure there is adequate airflow and protection against moisture from the concrete slab below.
Building Codes and Standards: The method used should comply with local building codes and standards, which typically specify requirements for suspended floors, including materials and construction techniques to ensure safety and durability.
Use of Adjustable Timber Cradle Support: Adjustable timber cradle systems are often used for their ability to provide a stable, level, and adjustable base for timber joists. This method is widely regarded as a more appropriate and reliable solution for creating suspended timber floors over concrete slabs, offering easier adjustability and better load distribution.
Given your concerns, it might be wise to:

Consult a Structural Engineer or Flooring Specialist: Get a second opinion from a professional who can assess the installation's integrity and advise on the best course of action.
Review the Contractor’s Method Against Building Codes: Ensure that the construction method meets local building regulations and standards for suspended floors.
Discuss Concerns with Your Contractor: Bring up your concerns directly with your contractor, asking for an explanation of the chosen method and how it aligns with best practices and standards.
If the method used is indeed found to be substandard or not in compliance with building codes, you may need to discuss remediation steps with your contractor to ensure your floor is safe, durable, and properly installed.

Hi there, the method they have used is okay. If packed correctly (every 4 foot), being secured down to the concrete and being secured to the wall at wither side using brackets then, there will be no issues whatsoever.

Certainly! Let’s address your concerns regarding the installation of suspended timber floors. While I’m not a qualified structural engineer, I can provide some general insights based on industry guidelines and best practices.
Method Used:
The method your contractor has employed seems unconventional and may not align with standard practices. Using cut pieces of ply boards, tongue and groove floorboards, and packers as a base on top of a concrete floor slab is not typical for suspended timber floors.
Suspended timber floors are usually constructed with a more robust and consistent support system.
Adjustable Timber Cradle Supports vs. Other Methods:
Adjustable timber cradle supports (also known as adjustable pedestals or cradles) are commonly used for supporting suspended timber floors. These supports allow precise leveling and adjustment.
Here are some considerations:
Adjustability: Adjustable cradle supports can be fine-tuned to ensure a level and stable base for the timber floor.
Uniformity: Using cut pieces of various materials (plywood, tongue and groove boards, etc.) may result in an uneven surface, affecting the stability and load distribution.
Durability: The longevity of the floor system depends on the quality and durability of the materials used. Plywood and floorboards may not provide consistent support over time.
Load-Bearing Capacity: The 8mm adjustable decking pad may not be sufficient to support the weight of the timber floor and any additional loads (e.g., furniture, occupants).
Industry Standards and Guidelines:
NHBC Standards (National House Building Council) provide guidance on construction practices. While they don’t explicitly specify adjustable cradle supports, they emphasize proper construction, leveling, and load-bearing capacity.
NHBC standards require that upper floors be constructed in a workmanlike manner and provide satisfactory performance1. Deviations from standard practices should be carefully evaluated.
Consult a Professional:
Given the complexity of suspended timber floors and potential long-term implications, I recommend seeking professional advice.
Structural engineers, architects, or building surveyors can assess the installation, verify its compliance with regulations, and recommend corrective actions if necessary.
They can also evaluate load-bearing capacity, material suitability, and overall safety.
Document the Installation:
Take detailed photographs of the installation, highlighting the areas of concern.
Keep records of communication with your contractor and any concerns raised.
Remember that your safety and the structural integrity of your home are paramount. Consult with a qualified professional to assess the situation and determine the best course of action.