Roof renevation

1.    Studies and repair plans

A roof repair will often be considered in a situation where there is problem on the roof. The reasons for problems must be clarified at this stage so that the correct things can be fixed.

Sometimes the leaking water of the roof is not caused by the water membrane as such. The waters leaking inside may be caused, for instance, by badly sealed inlets or ventilation and defrosting equipment.

The most difficult problems are those caused by condensation water. The moisture of the room air may pass through a weak vapour barrier to the structures, where it condensates to a cold surface. Such condensation water may puddle up in structures and even freeze. Then, when it melts, it will find its way back inside in the form of water. The condensation problems often come up after a cold freeze, as the weather gets warmer, or during springtime, as the snows melt. Repairing the vapour barrier after the fact is very difficult, depending on the structure, but the problems may be reduced by improving the ventilation of the roof structure. 

In some cases, a leaky roof may be fixed by patching it or performing partial repairs. At other times, it is more sensible to repair the entire roof. 

The repair plan is an important document, as, without a plan, it is very difficult to organize a competitive tendering for those performing the repair. With a decent plan, the performers have the same opportunities for tendering and it is considerably easier to compare the offers. 

When performing a roof repair, it should be considered whether it would also be sensible to also fix other matters. In old houses, the lengthening of the eaves, further thermal insulation, rain water system repairs and other such procedures should often be combined with the roof repair process.  The plan should contain, at least

  • the target information
  • possible original drawings
  • sufficient data on the old structure
  • applied new materials
  • applied directions

2.    Selecting the performer of the repairs

With a good repair plan, it is easy to compete those performing the repair and select the most suitable one. A repair plan can also offer help for a do-it-yourself builder.

Competitive tendering of a repair is usually worth the effort, but also includes a risk of bad quality. When doing so, it pays to be certain that different offers really match each other. The cheapest price does not necessarily always mean the best end result.

There are many operators performing roof repairs, and many companies possess a sufficient know-how to successfully implement projects. In some cases, the seller of the repair offers both a quality study, the plans and the actual operations as one package. In such cases, you should ensure that the seller is really a professional roofing expert, not just someone trying to get a large deal. In some cases, an aggressive door-to-door salesperson may try to get you to sign the deal immediately, so that you cannot ask for a competing offer elsewhere. Take such salespersons with a grain of salt.

Katepal recommends the repair companies of the Katepal Kattajat chain.  

Kattoliitto has created a checklist for those performing the roof repair.

3.    Work

During the work phase, you should pay attention to the weatherproofing and ensure that the contractor has prepared for bad weather.

In some cases, you can leave the old membrane under the new membrane, but the old membrane often has to be dismantled. The benefit of dismantling is that the possibly damaged parts should be repaired, without any surprises being left inside of the structure.

The dismantling phase starts with the removal of the old membrane. Sometimes the old membrane may contain asbestos. In these cases, it should be ensured that the dismantling is performed as ordered and the waste is delivered to a proper location.

In the dismantling phase, there may be problems which were not possible to take into account without opening up the structures. For such situations, you should have a contract regarding the extra work. The busiest operators might just put a new membrane on top of old problems. In this case, it is possible that the new membrane will last considerably a considerably shorter period than intended.

During the initial phase of the project, you should review whether all the agreed work stages are ready and in accordance with the agreement. It often is sensible to use a construction professional to monitor this to ensure that the work has been performed according to good construction practices. 

4.    New roof

When the new roof is ready, the constructing party should relinquish the maintenance directions of the roof to the customer. A decent maintenance of the roof increases its use time considerably.

The warranty conditions should also be reviewed and it should be ensured that the contractor is truly responsible for the roof as agreed.