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Treatment of dry rot: this fungus which destroys walls and cellars in our homes

What is dry rot

Dry rot is a fungus that develops in the presence of moisture on different materials of cellulosic origin present in our homes: untreated wood, paper or cardboard.

During its proliferation, the dry rot feeds on the wood and spreads through the walls where it finds the mineral salts and moisture necessary for its development.

Hydrotec offers a complete and specific treatment against dry rot attack. After diagnosis and demarcation of the affected area, the cause of proliferation must before anything else be eliminated.

Where ?

  • Dry rot mainly develops in poorly ventilated, dark and humid areas where its food is present, namely wood and its derivatives. It often appears as a result of moisture problems and leaks of various origins such as sanitary leaks, leaks from roofs, sewers; capillary rise or moisture problems in the cellar. We find dry rot: In damp rooms with poor ventilation, in the presence of woodwork (lumber or furniture, paper, cardboard): cellars, floors, stairs, door frames in contact with a damp wall, etc. In dilapidated roof timber frames: when the roof is damaged, water infiltrates and moistens the woodwork, which becomes fertile ground for the proliferation of the fungus. Dry rot mainly develops in poorly ventilated, dark and humid areas where its food is present, namely wood and its derivatives. It often appears as a result of moisture problems and leaks of various origins such as sanitary leaks, leaks from roofs, sewers; capillary rise or moisture problems in the cellar. We find dry rot :
  • In damp rooms with poor ventilation, in the presence of woodwork (lumber or furniture, paper, cardboard): cellars, floors, stairs, door frames in contact with a damp wall, etc.
  • In dilapidated roof timber: when the roof is damaged, water infiltrates and moistens the woodwork, which becomes fertile ground for the proliferation of the fungus.

Symptoms

  • Crumbling of affected woodwork.
  • Blistering of paint on wood
  • Appearance on the surfaces of a strong-smelling fungus similar to a yellowish-brown foam surrounded by a white foam
  • Presence of whitish or grey filaments (rhizomorphs of the mycelium) several millimetres thick through wood and masonry
  • If appears to disappear, it can in reality survive in dormant form while awaiting the return of conditions conducive to its development (lethargy). .

Why do it ?

– Stop dry rot in its destructive progression and thus prevent degeneration of the timber (into cubic rot) causing greater damage such as collapses, health problems, etc …
– Our approach is global and preventive: we remove the dry rot, but also tender for the repairs and remedy some of its causes (rising damp, moisture in the cellar).
– We use products that are non-toxic to humans.
– Our products are officially recognized by the Ministry of Health.
– Hydrotec offers a 10-year guarantee on the dry rot treatment.

Processing steps of dry rot treatment

1

Diagnostic

identification and location of the focus of dry rot. Sample collection and laboratory analysis

2

Factors search

causing the appearance of dry rot and delimitation of the area to be treated

3

Preparation for treatment

  1. Evacuation of infested wood
  2. Stripping of plastering and brushing of walls
  3. Replacement of contaminated woodwork

4

Curative treatment of the affected area

  1. Drilling of walls
  2. Injection and spraying of the fungicidal product
  3. Treatment of neighboring woodwork by spraying fungicide / insecticide product.

5

Replacement or reinforcement of joists

6

Renovations

plastering, various joinery

FAQ – find out more

Definition
The dry rot is a fungus. The term dry rot is the common name for “Serpula lacrymans” which, in mycology, is attached to the order Basidiomycetes. It is the root cause of the majority of attacks by lumber in our homes. The ramifications of this wood-eating fungus develop in the dark, in the presence of moisture, wood, cellulose (cardboard, paper).
Development conditions

The development of dry rot mycelium is promoted by

  • A moisture content of the wood between 22 and 40%
  • A temperature between 20 and 26 ° C.
  • A confined space away from light

At the fruiting stage, the rust-colored carpophore (or “sporophore”) forms and appears in the open air to allow the spores to swarm.
Dry rot causes a very characteristic cubic rotting of the wood.
Very stubborn, dry rot can spend many years in lethargy while waiting for favorable conditions for its redeployment.

Why is it developing?

To develop dry rot needs water. Its development is most often the consequence of a leak (pipe leak, faulty bath or shower tub seals, sewer leaks) or a structural moisture problem (rising damp, moisture in cellar, roof leak. ).
Thanks to its very active filamentarynetwork (rhizomes), when the temperature is favorable, its rhizomes grow rapidly in the walls, in search of food.
Wood affected by dry rot show significant swelling and cracks; the wood is literally cut into large cubes by the fungus, which leads to an irreparable loss of strength of the wood worked.
Dry rot destroys the wood present in its path: joists (or gîtes), wooden lintels, stairs, landings, door frames.
Like the house capricorn, dry rot is a plague that causes significant damage because it attacks directly the supporting elements of buildings.

What does dry rot eat?

Dry rot feeds on cellulose found in wood. It mainly attacks softwood species (conifers): spruce, northern red fir, Douglas-fir, etc. Softwoods are widely used for the construction of our habitats.
Dry rot also appreciates cardboard, paper, wooden crates (we think of crates of wine bottles stored in the cellar), pallets, firewood stored against the walls or on the damp floor, old furniture … all the objects made of cellulose that we often store in our cellars.
its temperature rarely drops below 5 ° C.

  • the cellar is a dark and humid place.
  • its temperature rarely drops below 5 ° C.
  • cellulosic material is often stored there.

In the event of an insidious water leak, dry rot also grows very easily between joists that support a floor, or in an attic.

Related attacks

Wood damaged by dry rot is also colonized by larvae of wood-eating insects such as the Big Woodworm.
During an attack by dry rot, treatment of thewood of Framing adjacent to the dry rot focus is essential. This treatment is carried out with a curative fungicide / insecticide product.

Difference between preventive treatment and curative treatment

A preventive treatment is generally carried outin the factory, by soaking or sprinkling new wood (still healthy) using a wood protection product called a preventive fungicide and insecticide. This treatment prevents further attacks by fungi and wood-eating insects.

Unlike preventative treatment products, curative treatment products eradicate insects and fungi that are already present on or inside woodwork.
In general, treatment by spraying with a curative product is sufficient to permanently stop an attack. But in the event of an attack by the house capricorn (a beetle insect that develops as a larva in dry coniferous woods), the disinsection of the wood will be carried out by practicing biocidal injections in the affected pieces of wood.

How to treat dry rot?
Combating this pest fungus requires substantial preparatory work. To treat a building attacked by dry rot, you should:

  • Address the moistureproblem that allowed the fungus to develop.
  • Strictly circumscribe the area of ​​intervention. To do this, we strip the walls and ceilings by locating the rhizomes (filamentary network). The stripping is continued in all directions, one meter beyond the last appearance of the rhizomes.
  • Dismantle all wood affected by the fungus: joists, stairs, jambs, lintels, etc. Any wood that shows signs of worm, cracks, cubic rot or sawdust must be replaced.
  • When the stripping and the dismantling are carried out, the walls receive a treatment by injection of curative fungicide product.
  • Wood protection: spraying a curative insecticidal fungicide product on all adjacent maintained wood.
  • Replace the dismantled wood with new pieces of pre-treated wood bath. Special sealing precautions are taken for new joists anchored in masonry.
  • The wooden lintels affected by the fungus are replaced by concrete lintels.
  • As a precaution against residual salts and moisture (the walls have often been dampened in the event of dry rot), we recommend applying a remediation cement before plastering the walls.
  • After all this demolition and treatment work, the restoration work can be undertaken without the risk of the reappearance of dry rot: installation of ceilings, floors, door timber, frames, stairs, wall plasters, etc.