— Delirious New York Diary

千葉県多古町の古民家改修 その2. 建物の現状と改修点 Current condition of the building and its issues

IMG 0768 千葉県多古町の古民家改修 その2. 建物の現状と改修点  Current condition of the building and its issues

屋根の出し桁 軽い屋根を前提とした平屋造りであれば、ここまでの構造にする必要はない 元々は茅葺屋根が載っていただろうとのこと Extended beam of the roof frame. For light-weighted roof on one-story high building would not need such structure. There seemed to be fitted with a thatched roof with heavy weight.

まずは、建物の状態を大工の棟梁と一緒に確認していく。 畳や床の野地板を剥がして構造を見ると、元々は8畳二間 (4坪) にユーティリティ、のいわゆる「長屋」だったものに、6畳二間、下屋になった廊下、その他風呂場や台所を増築しているのがわかる。この8畳二間部分の構造部材はかなり古く、また竹編みの土壁の状態から考えても戦前のもので、築80年以上はたっているようだ。増築部分は部材がかなりチープで、構造も最小限、仕上げもプリント合板などが使われていることから、増築は戦後しばらくたってからのものと考えられる。風呂まわり、トイレまわりはコンクリートブロック積みのため、かなり最近加えたものだろう。


First of all, the condition of the building needs to be judged–master carpenter is in charge here. As we looked at the structure of the building after removing floor, it became clear that originally the building has two main rooms (eight tatami-mat space = about 13 sqm) with other utility spaces, and additional rooms (6 tatami-mat space = about 10 sqm) and corridor gallery, bathroom, kitchen were added later. The original part appears to be quite old as we looked at its structure materials, probably built much earlier than the WW II–more than 80 years old. The additional part has much cheaper, less costly materials with newer finish, therefore it was done after the war. Bathroom area is the only part in this building with concrete blocks, thus that part was added quite recently.

The most attractive part of this building is its roof structure. Roof frame has extended girder exposed to the exterior of the building, probably because the original roof was a thatched roof with heavy weight. This roof frame is partially exposed inside of the building, and its beams and girders are quite massive for one-floor building. Visible frames are quite impressive and beautiful.

IMG 0582 千葉県多古町の古民家改修 その2. 建物の現状と改修点  Current condition of the building and its issues


We tried to decide which part of the building should be fixed for now, within the tight budget.

1. 屋根:屋根は現在は古いトタンで葺かれている。赤いペンキを塗ってあるものの錆が盛大に出ているため、全て張り替えることになった。また野地板がきちんと張られていないため、錆びたトタンの隙間から一部雨漏りがしている。野地板を含めた張替えとなる。

1. Roof : currently the roof is finished by a corrugated tin roof material, later painted by red paint. However, now rust is damaging the entire roof. In addition, sheathing boards were not well executed and the boards were too small to cover as the base of the roof, thus the rain water is leaking from the corroded roof. Entire roof needs to be redone from the sheathing.

DSC5548 千葉県多古町の古民家改修 その2. 建物の現状と改修点  Current condition of the building and its issues

小屋組 切妻屋根だが、出し桁構造とするため屋根の四隅へと伸びる構造材が入っている。 Roof frame–alghough the roof is in gable shape, supporting heavy roof required to add supporting beams pointing toward the corners of the roof.

2. 基礎:予算の潤沢にある人が行うことの多い古民家改修では、大抵の場合ベタ基礎や布基礎で建物下全面を固め、耐震性や断熱性の向上を図る。ただ、階高があり瓦葺きなどで屋根が重い建物ならともかく、この平屋でトタン葺の建物にはどうだろうか。また古民家のような床下の通気性が木構造を湿気から守っている作りに対して、床下全面をコンクリートで固め、土台などの構造材をコンクリートに直置きすることが良いことなのか、疑問ではある。 今回は、必要であればコンクリートのブロックや柄を置く程度に留めることとした。予算の都合でもある。

2. Foundation : most of the recent renovation projects of old residential buildings in Japan, entire foundation is redone by mat/ continuous foundation beneath the building, in order to fulfill seismic / thermal insulation performance. However, this building is a one-floor building with light roofing–and I am uncertain about the continuous foundation for such old residential building in Japan, which maintains dryness by ample air flow beneath the floor to protect the base wooden structure. In this case, we will simply add some concrete base at certain points as we add more base wooden structure.

3. 構造:古い部分はしっかりしている方だが、それでも床下で家の歪みを抑える大引などの水平構造部材は少ないし、筋交いもない。増築部分はさらに細い部材しかはいっていない。このため、今ある大引の間に数本追加していく。

3. Structure : the original part of the building has a solid structure with good wooden structure pieces, but the added part has much thinner pieces. We decided to add more joist in both original part and the added part for more rigidness of the structure.

4. 建物の歪み:基礎や構造の問題から来るもので、現状、家の中に立つと一番不快なのはこの点である。一番高い現状床高を測り、それに合わせて他の部分をジャッキで持ち上げ、基礎ブロックなどを積み増して水平出しする。

4. Distortion of the building : this is quite noticeable and uncomfortable. By finding out the highest point of the current floor level, sunk, lowered parts will be lifted by jacking up the structure, and adding additional foundation blocks in order to achieve horizontality of the building floor.

5. 内装:畳の傷みはそれほどでないものの、床は全面板敷きに変更する。実際、床下に石積みの囲炉裏跡などがあったことから、元々は板敷きだったと思われる。これにより、廊下も含め建物全体がひと続きになる。 壁などは現状の構造の上にやり直しになる。元は外壁だった土壁は構造でもあるため残し、仕上げを変更するに留める。 現在、棟梁と話し合っているのは8畳二間の天井の扱いだ。屋根の雨漏りによりかなり傷んでいる部分がある。できるならばこの部分の天井も抜き、小屋組構造を見せたい。この件については、屋根を剥がして状態を見てから決定することにした。 その他、玄関まわり、壁のない東側へのサッシ取り付け、建具の補修などひと通り行う予定となっている。

5. Interior finishes : the tatami-mats on the floor were not so damaged. However, we decided to change the finish for wooden floor. Actually, there were two stone-piled fireplace on the floor, therefore originally the floor appeared to be finished in wood. Entire building will be continuous after the finish. Interior wall is found only at a few point in the building. Papered sliding doors (shoji) were everywhere, and diffused light coming into the room nicely–thus we will fix all the shoji doors for now to separate rooms. Bamboo reinforced clay walls will be left as is, while its surface finish needs to be redone–in either mortal or dry panel finish. The biggest issue is the interior roofs of the main rooms. Some parts are quite damaged by the rain leak from the roof, and I would love to expose the roof frames to see and enjoy. We need to judge after removing the roof. Other parts–entrance, window sash, and fitting fixtures will be fixed slightly.

IMG 0563 千葉県多古町の古民家改修 その2. 建物の現状と改修点  Current condition of the building and its issues

6. 設備:トイレや風呂、台所といった設備部分については、間取りも含め全部やり直しとなる。合併浄化槽の設置により排水をまとめるのが最重要。風呂については、現状の窓などを活かし切れないユニットバス導入は見送り、モルタル・木仕上げなどにする。台所には竈があったものの、さすがに使い切れないのとそれほどの年代ものではなかったため取り除く。電気は配線を一部やり直す程度で使える状態にある。

6. Equipment : toilet, bathroom, kitchen with equipment need to be redone completely, with floor plan alteration. Septic tank needs to be set. Unit bathroom is the quickest solution to add modern bathroom, but it can not utilize current windows, thus we simply change the finish of the concrete blocks and place a tub. Of course, bath heater (oil) will be added for modern bathroom. Kitchen will be placed with new sink and propane gas. Electric wiring needs to be redone at some part of the building. Lighting fixture will be changed for more suitable ones.



For this renovation project, we can not focus on the high finish quality of interior finish–designing shall be restrained (well, it will be difficult for myself to control it, but..) and I should discuss and follow the decision with the master carpenter. The back yard of the building is so big, and in the future it is possible to build annex to this building.

DSC5547 千葉県多古町の古民家改修 その2. 建物の現状と改修点  Current condition of the building and its issues

敷地西面は全面、竹林になっている 傾斜面を竹が地盤固めしてくれる 青竹の愛だから木漏れ日も射す West side of the territory with bamboo trees. The slight hilly condition is secured by the bamboo roots, while the sun light comes through among green bamboo.


From next time, I will be reporting the progress of the renovation.

Submit comment

Spam Protection by WP-SpamFree