Newport · Gwent
Floor joist repairs in Newport
If a plumber or electrician has recently had the boards up at your Newport home, the joists they worked around are worth a look. Deep notches and holes in the wrong place weaken joists quickly, and sistering them is usually a short, tidy job.
Guide price from£230per joist inc VAT

- Postcodes
- NP10, NP19, NP20
- Population
- about 160,000
- Area
- Gwent
- Pricing region
- Wales
What should you know about the ground under Newport?
Newport (NP10, NP19, NP20) has around 160,000 residents and sits in Gwent. We also take enquiries from nearby Risca (5 miles), Cwmbran (5 miles) and Abercarn (7 miles).
Clay soils are found in parts of Gwent. Historic coal workings are recorded beneath parts of Gwent, and a coal mining search is worth checking where movement is unexplained. Typical buildings in Gwent: Valley terraces on steep hillsides, Victorian houses in Newport and Abergavenny, and post-war estates.
Which repair method suits a home in Newport?
Sistering a joist
A new length of treated timber, the same depth as the original, is bolted or screwed alongside the damaged joist so the two share the load. It is the quickest fix for a notched, cracked or sagging joist that is otherwise sound, usually after lifting a few boards.
Best for: Cut, cracked or sagging joists with sound ends
Splicing ends and fitting hangers
Where only the end has rotted, it is cut back to sound timber and a new piece is fixed alongside, bearing on the wall or on a new joist hanger. Missing or under-nailed hangers elsewhere are replaced at the same time. The damp in the wall must be fixed too.
Best for: Rotten joist ends in damp solid walls
What happens when we carry out floor joist repairs in Newport?
Photos and a call
Send photos of the dip or soft area, the outside wall at ground level and any air bricks. A short call about when it started, and any recent plumbing or heating work, tells us whether the problem is local or widespread.
Written quote
You get a no-obligation written quote listing which joists are sistered, spliced or replaced and any sleeper wall or ventilation work. It becomes a fixed price in writing once the repair is specified.
Repair the structure
Boards are lifted and numbered if they are going back, and rotten timber is cut out. New treated timber is fixed and checked with a level before strutting, hangers and any restraint straps go in.
Signs you may need floor joist repairs
- A musty smell, or fungal strands showing between the boards
- Soft or spongy boards near outside walls, hearths or the bathroom
- A gap opening up between the skirting board and the floor
How much will floor joist repairs cost in Newport?
For Newport we use Wales rates. Treat the table as a budget guide, inc VAT; the price you pay is the one on your written quote.
| Item | Guide price | Per |
|---|---|---|
| Splicing or sistering a damaged joist | £230 – £370 | per joist |
| Whole room of joists and boards | £1,850 – £5,500 | per room |
| Sleeper wall rebuild and ventilationest. | £370 – £1,400 | per room |
Rules for floor joist repairs in Wales
In Wales, small like-for-like repairs do not usually need approval, but work that alters or strengthens the structure needs building control under the Welsh Building Regulations, and the Party Wall etc. Act 1996 can apply to shared walls.
Floor joist repairs in Newport: questions and answers
What is the price of floor joist repairs in Newport?
Guide prices for floor joist repairs in Newport start from about £230 per joist, including VAT, on Wales rates. Your fixed written price follows photos or a survey and depends on the extent of the work and access.
Do you carry out floor joist repairs in Newport?
Yes. We take enquiries from across Newport, including NP10, NP19, NP20, and from nearby places such as Risca and Cwmbran. Send photos for a free initial view and we will tell you what happens next.
Does the ground around Newport cause cracking?
The valleys of Blaenau Gwent, Torfaen and Islwyn lie on the South Wales coalfield with extensive historic workings and spoil tips, while Newport and Monmouthshire have Mercia Mudstone, alluvium and Old Red Sandstone. Only an investigation can say why a particular building has moved.
What is sistering a floor joist?
Sistering is fixing a new length of timber alongside an existing joist so the two share the load. It strengthens a notched, cracked or sagging joist without removing it, so it is quicker and less disruptive than replacement.
What causes rot in floor joists?
Damp causes almost all joist rot. Joist ends in damp walls, voids with blocked air bricks, leaking pipes and high outside ground levels keep timber wet enough for fungi to grow. Replacing timber without fixing the damp usually means the rot returns.
More repairs we carry out in Newport
- Lintel replacement
- Underpinning
- Boundary and garden wall repairs
- Concrete repairs
- Structural surveys and crack monitoring
Floor joist repairs near Newport
Each joist, sleeper wall and air brick at your Newport property is itemised in the written quote, then fixed in price once the repair is specified.