ᐅ Soundproofing Interior Wall with Wood Fiber / Interior Doors

Hello,

we are currently insulating our interior walls, which have 12cm (5 inch) wooden studs, with 80mm (3 inch) wood fiber mats SteicoFlex WLG40. This was included in our interior finishing package. Now we are considering whether to add an additional 40mm (1.5 inch) wood fiber board in the "critical" rooms such as the transition areas between the children’s room/bedroom/bathroom for sound insulation. Does this make sense, or would the additional benefit be minimal? Is it possible to quantify this in terms of a measurable unit like decibels? I couldn’t find any information about this in Steico’s technical datasheets.

On Friday, we had the selection appointment and discussed the interior doors. The consultant recommended solid core doors instead of hollow core for the mentioned rooms, also due to sound insulation reasons. However, we have installed a controlled mechanical ventilation system, which means the door panels would need to be trimmed to allow air exchange. This raises the question again if solid core doors still make sense in this case.

A solid core door is definitely a good choice. You don’t need to shorten the doors at the bottom because of the mechanical ventilation system. First, consider what type of doors they are and whether they are usually left open anyway.

Secondly, you can have the door routed out at the top of the frame, which is how we did it. This is much better for sound insulation and allows for good airflow in an invisible way!

This is the first time I've heard about shortened doors. They look terrible anyway...

The issue with shortened doors is not new, but there are other ways to ensure air exchange with controlled residential ventilation while still maintaining good sound insulation in the house.

For example, door frames or drop seals with an air gap can be used.

To achieve an airflow of 30 m³/h (about 18 cfm) through an 80 cm (31.5 inches) wide door, a gap of 0.7 cm (0.28 inches) is required. In the case of supply ventilation, the overflow opening should be located near the upper part of the room. Overflow openings integrated into a milled-out door frame offer an invisible solution here.

There are also special solutions for overflow openings in doors and masonry.

Hmm, okay, it seems I need to update my information about the overflow options. The milling out sounds relatively simple and cost-effective.

Does the advantage of solid core then offer me a significant added value? We were quoted an additional cost of about 70 EUR per door.

Full-core chipboard or hollow-core chipboard is not relevant at this point.

Sound is measured in decibels (dB), and doors have sound insulation ratings. You should ask your contact person what options are available.

However, you should first be clear about what you actually need.