Temporary works and propping design
Design of the temporary propping, needling and support needed to carry loads safely while alterations or demolition take place.
About this service
Every structural alteration has a moment when the old support has gone and the new one is not yet in place. Temporary works are what carry the building through that moment: props, needles, shoring and the order in which they go in and come out. Our temporary works design and propping scheme turns that stage into a planned, calculated operation rather than something improvised on the day.
Contractors are the main users of this service, especially where the permanent design does not cover propping in detail. Homeowners and project managers also ask for it when several walls are coming out at once, a chimney breast is being removed across more than one floor, or excavation is happening next to a neighbour's house. Party wall surveyors sometimes ask for a designed scheme before agreeing an award.
London buildings make temporary works especially important. Terraces share walls, so a problem in one house can quickly affect the next. Floors and walls in period properties are often weaker than they look, with soft lime mortar, decayed timbers or past alterations. Suspended timber ground floors cannot take prop loads unless those loads are carried down to firm ground beneath.
Temporary works designs go through the same three-step quality control as our permanent designs, with final sign-off by our Head of Engineering. The scheme is issued as clear drawings and notes that the site team can follow, and we can answer the contractor's questions as work proceeds. Fees start from £500 + VAT, and the fixed fee is confirmed in writing before work starts.
When you need it
- Walls, chimney breasts or floors are being removed
- Your contractor needs a temporary works design
- A basement or underpinning job needs propping
What's included
- Temporary works design
- Prop and needle sizing
- Sequence of installation and removal
- Drawings for the contractor
How it works
- Understand the permanent worksWe review the structural design, the existing building and the contractor's intended method, so the temporary scheme fits how the job will actually be built.
- Calculate the loadsWe work out what each prop and needle must carry, including walls, floors, roof and chimney loads, and the route by which those loads need to be taken down to firm support.
- Design the supportWe size props, needles, spreader plates and any shoring, and check that the floors and ground beneath can take the concentrated loads without damage.
- Set the sequenceWe set out the order of installation, removal of existing structure, new works and striking of props, with hold points where the contractor checks before moving on.
- Check and issueThe scheme passes our three-step quality control and Head of Engineering sign-off, then is issued as drawings and notes the site team can work from directly.
What you receive
Who is responsible for temporary works?
Responsibility for temporary works sits with the contractor carrying out the job. Larger sites usually have a named temporary works coordinator, but on domestic projects it is often the builder alone. A designed scheme gives them a clear method and gives you, as the client, confidence that the riskiest stage of the job has been thought through.
The most frequent issue is props standing on a timber floor or thin slab that was never meant for a point load. Loads need a path to solid ground, sometimes through several floors with props aligned above each other. Another is striking props too early, before mortar under padstones has gained strength or before new steel is fully packed.
On underpinning and basement jobs, temporary works are central to the design. See our underpinning design and sequence and basement structural method statement for how they link together.
Projects that used this service
Frequently asked questions
What are temporary works in construction?
Temporary works are any structure used to support or protect the building and the permanent works during construction, then removed. On domestic projects they usually mean props and needles holding up walls while a beam goes in, shoring to excavations, and supports for floors or chimneys. They are often as critical to safety as the permanent design.
Does my builder need a temporary works design?
For a single straightforward opening, a competent builder may follow the propping guidance in the permanent design. Where walls carry heavy or unusual loads, several elements are removed together, or the work affects a neighbour, a designed scheme is strongly advisable. If unsure, ask your engineer whether the existing design covers propping in enough detail.
How far apart should Acrow props be?
Spacing depends on the load being carried, the prop size and how far it is extended, the needle size and what the props stand on. There is no safe universal figure. A temporary works design calculates spacing for the specific wall and checks the floor or ground beneath can take the load.
What is a needle in propping?
A needle is a short beam, usually timber or steel, passed through a hole cut in the wall above the opening. Props on each side support the needle, which then carries the wall while the masonry below is removed and the new beam is installed. Needle size and spacing are part of the design.
How much does a temporary works design cost?
Our temporary works design and propping scheme starts from £500 + VAT. The price depends on how many elements are being supported, the loads involved and the complexity of the sequence. The fee is fixed in writing before any work starts.